Algebra Needed

[OldLady]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

 

[OldLady]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

 

[Tresha91203]

You must also know that P+I=A.

A=500(1+0.1x). so
P+I=500(1+0.1x)
500+100=500+50x
600=500+50x
100=50x
2=x

2 years (if it's *annual*). If they ask how many months, convert to 24.

Great I plugged in my numbers and came up with 28. I suppose it could be 2.3 years, but I didn't do any converting, so it shouldn't have come out months.
I give up on this formula.

Post the problem. You can rewrite the same formula this way (solved for t) if it helps:. t = (1/r)(A/P - 1)

 

[Tresha91203]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

 

[Tresha91203]

You must also know that P+I=A.

A=500(1+0.1x). so
P+I=500(1+0.1x)
500+100=500+50x
600=500+50x
100=50x
2=x

2 years (if it's *annual*). If they ask how many months, convert to 24.

Great I plugged in my numbers and came up with 28. I suppose it could be 2.3 years, but I didn't do any converting, so it shouldn't have come out months.
I give up on this formula.

If you plug your numbers into this, do you get the same answer? If yes, your answer is correct. If no, you erred in calculating.

Simple Interest Calculator A = P(1 + rt)

 

[OldLady]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

 

[Tresha91203]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

 

[Tresha91203]

12 months / 1.39=16.68 months, 1year+4.68 months

 

[martybegan]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

I'm an engineer, not an accountant, so what does simple interest imply? If it implies what the equation above does, i.e. calculate the interest as over the period of the loan on the total primary, not as calculated on the remaining primary per time period, than I think the equation above works.

 

[Tresha91203]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

I'm an engineer, not an accountant, so what does simple interest imply? If it implies what the equation above does, i.e. calculate the interest as over the period of the loan on the total primary, not as calculated on the remaining primary per time period, than I think the equation above works.

Yes, that's simple interest. If compound interest, it's different. There are different compound interests, too, but irrelevant to a simple interest question.

 

[martybegan]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

I'm an engineer, not an accountant, so what does simple interest imply? If it implies what the equation above does, i.e. calculate the interest as over the period of the loan on the total primary, not as calculated on the remaining primary per time period, than I think the equation above works.

Yes, that's simple interest. If compound interest, it's different. There are different compound interests, too, but irrelevant to a simple interest question.

Thank you.

I keep forgetting it's not only engineers that like to complicate basic algebra, Accountants love to do it too.

 

[OldLady]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

Thanks, Tesh. I'm following you through 700=600+72t
then you lost me.
How did you get 100=72t?
From there, I get how you got 1.39.
It was that step from line 3 to line 4 that lost me.

 

[Dekster]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

It isn't really 9th grade algebra for a problem like this. OP has moved over into to the trig/calculus area.

 

[OldLady]

You must also know that P+I=A.

A=500(1+0.1x). so
P+I=500(1+0.1x)
500+100=500+50x
600=500+50x
100=50x
2=x

2 years (if it's *annual*). If they ask how many months, convert to 24.

Great I plugged in my numbers and came up with 28. I suppose it could be 2.3 years, but I didn't do any converting, so it shouldn't have come out months.
I give up on this formula.

Post the problem. You can rewrite the same formula this way (solved for t) if it helps:. t = (1/r)(A/P - 1)

I would never in God's name remember that or be able to explain why it works to a student. lol

 

[OldLady]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

It isn't really 9th grade algebra for a problem like this. OP has moved over into to the trig/calculus area.

That makes me feel slightly better. I'm not sure it's really all that complicated, though.

 

[Dekster]

You must also know that P+I=A.

A=500(1+0.1x). so
P+I=500(1+0.1x)
500+100=500+50x
600=500+50x
100=50x
2=x

2 years (if it's *annual*). If they ask how many months, convert to 24.

Great I plugged in my numbers and came up with 28. I suppose it could be 2.3 years, but I didn't do any converting, so it shouldn't have come out months.
I give up on this formula.

Post the problem. You can rewrite the same formula this way (solved for t) if it helps:. t = (1/r)(A/P - 1)

I would never in God's name remember that or be able to explain why it works to a student. lol

To show a student, you should simplify the problem to $10/month 12% interest and $100 borrowed and run the calculation month by month by month. 12% makes it an easier 1% per month and won't take a month of sundays to do each month's manually for such a short payback time.

 

[Dekster]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

It isn't really 9th grade algebra for a problem like this. OP has moved over into to the trig/calculus area.

That makes me feel slightly better. I'm not sure it's really all that complicated, though.

It is because the problem is fixing the payments. If it were just how much would your payment be if your loan is 24 months is is a lot less convoluted mathematically.

 

[OldLady]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

It isn't really 9th grade algebra for a problem like this. OP has moved over into to the trig/calculus area.

That makes me feel slightly better. I'm not sure it's really all that complicated, though.

It is because the problem is fixing the payments. If it were just how much would your payment be if your loan is 24 months is is a lot less convoluted mathematically.

Exactly. That is what we had been doing. No problem. This is why I HATE MATH. Tricky damned teachers.

 

[Dekster]

Again you need people not these people

bones, I am beginning to think this is true. There has to be someone here who can do this, though--they tried from 9th grade on to teach me how.

It isn't really 9th grade algebra for a problem like this. OP has moved over into to the trig/calculus area.

That makes me feel slightly better. I'm not sure it's really all that complicated, though.

It is because the problem is fixing the payments. If it were just how much would your payment be if your loan is 24 months is is a lot less convoluted mathematically.

Exactly. That is what we had been doing. No problem. This is why I HATE MATH. Tricky damned teachers.

i loved math, it was black and white, right or wrong unlike say history or english. 2+2=4 was more appealing than "What is the symbolism of the scaffolding scenes in The Scarlet Letter" or good lord, "What was the main cause of the Civil War"

 

[Tresha91203]

That's not to say Tresha and Moon and Fueri aren't doing it right--they just can't explain it in a way I, the Math Moron, can understand it. Simple procedural steps. Oh so simple.

Check the wording of the problem. It may be a "gotcha" problem. The formula is correct. For instance, is there any wording that would indicate you need montly numbers rather than annual?

The wording is exactly the same as what I posted, but the numbers are:
George is going to borrow $600 at 12% APR simple interest. He wants his total interest payment to be at most $100. What length of time can he take out the loan if that is the most he wants to pay on interest?

P+I=P(1+0.12t)
700=600(1+0.12t)
700=600+72t
100=72t
1.39=t

Thanks, Tesh. I'm following you through 700=600+72t
then you lost me.
How did you get 100=72t?
From there, I get how you got 1.39.
It was that step from line 3 to line 4 that lost me.

I need to isolate t so that it is alone ... t=
In order to do that, I have to get rid of the +600 attached to 72t, then get rid of *72 so that t is alone. Whatever I remove from one side of the equation, I MUST also remove from the other side of the equation or the equation is different.

700 = 600 + 72t I need to get t by itself
-600 -600
-------------------------------
100 = 72t
To get t alone, I have to undo 72*t. To reverse t*72, I divide by 72....Both sides
100/72=72*t÷72
On the right, the 72's cancel out, leaving t by itself