# What would be w? Proportions question

• Sep 29th 2012, 11:17 AM
Rune
What would be w? Proportions question
3 / 8 = w / w + 2
3 over 8 equals w over w + 2

3 w
_ = _

8 w+2

What is w? My answer is w = 1.2 but I'm not sure.
• Sep 29th 2012, 11:22 AM
MarkFL
Re: What would be w? Proportions question
Yes, that's correct.

$\displaystyle \frac{3}{8}=\frac{w}{w+2}$

Multiply through by $\displaystyle 8(w+2)$:

$\displaystyle 3(w+2)=8w$

$\displaystyle 3w+6=8w$

$\displaystyle 5w=6$

$\displaystyle w=\frac{6}{5}=1.2$
• Sep 29th 2012, 11:32 AM
Rune
Re: What would be w? Proportions question
132 / 35 = 12 / a + 1
132 over 35 equals 12 over a + 1

35(12) = 132(a+1)
430 = 132a + 132

Do you mind telling me how to get a? Can I subtract 132 from both sides then divide by 132a?
• Sep 29th 2012, 11:38 AM
MarkFL
Re: What would be w? Proportions question
You should have:

420 = 132a + 132

You are almost right...subtract 132 from both sides then divide by 132, this will isolate a and give you its value.
• Sep 29th 2012, 11:42 AM
Rune
Re: What would be w? Proportions question
298 = 132a

Now I divide 298 by 132a (132a by 132) and I get this.
2.257575757575758 = a

Is there anyway to make this into a fraction instead?
• Sep 29th 2012, 11:53 AM
MarkFL
Re: What would be w? Proportions question
You found: $\displaystyle 420=132a+132$

$\displaystyle 288=132a$

$\displaystyle a=\frac{288}{132}=\frac{12\cdot24}{12\cdot11}= \frac{24}{11}$