# Basic algebra question

• Mar 12th 2011, 05:23 PM
algebrahelpneedplox
Basic algebra question
I don't know what kind of algebra question this, hence the general title, but its easy, I just can't figure it out.

here goes:

15000(p-1.6) = 2000

p = ?

All help appreciated, thanks.

edit: btw, there's a "times" between the 15000 and the bracket so its: 15000 times (p-1.6) = 2000 and solve for p.
• Mar 12th 2011, 05:37 PM
cuteangel
To Solve for p, you basically need to multiply the 15000 into the brackets to get:
15000p - 24000 = 2000

Can you solve this equation from here?
• Mar 12th 2011, 06:04 PM
algebrahelpneedplox
Yeah got it. I don't know if my working is correct, but I took what you said and then I had:

15000p - 24000 = 2000

p - 24000 = 2000 / 15000

2000/15000 = 0.133333333

15000 x 0.133333333 = 2000

therefore p = (1.6+0.133333333) = 1.7333

again my working is probly wrong and wonky, but looks like I got the right answer ?
• Mar 12th 2011, 06:10 PM
cuteangel
Yes you got the right answer. However, you should always move all constants (in this case 2000 and 24000) to the side of the equation without the variable (in this case p) before you divide.

Therefore you would get:
15000p = 2000 + 24000
15000p = 26000
p = $\frac{26000}{15000}$

Therefore p = 1.73333
• Mar 12th 2011, 06:16 PM
Prove It
Sorry, but that is not correct.

If you have expanded the brackets to get

$\displaystyle 15000p - 24000 = 2000$

the first thing you need to do is undo the $\displaystyle -24000$.

So $\displaystyle 15000p = 26000$

$\displaystyle p = \frac{26000}{15000}$

$\displaystyle p = \frac{26}{15}$.

The alternative way to do it would be to divide both sides by $\displaystyle 15000$, rather than expanding...

$\displaystyle 15000\left(p - \frac{8}{5}\right) = 2000$

$\displaystyle p - \frac{8}{5} = \frac{2000}{15000}$

$\displaystyle p - \frac{8}{5} = \frac{2}{15}$

$\displaystyle p - \frac{24}{15} = \frac{2}{15}$

$\displaystyle p = \frac{26}{15}$, which is the same answer.
• Mar 12th 2011, 06:48 PM
algebrahelpneedplox
Ok, I understand now how to solve it.

Thanks.