# Math Help - Need a little help.

1. ## Need a little help.

I need help with the below problems. I don't understand how to find the common denominator when there is a variable as a denominator.

How do I work this on paper?

1/2 + 2/x = 3/4

Another problem I need help with is the below. I was able to figure out the answer, which is 29/10 but if I plug that into x to check the problem I have no clue how to work that.

x+1 over 3 + x+2 over 7 = 2

KN

2. 1/2 + 2/x = 3/4
(x+4)/(2x) = 3/4
4x + 16 = 6x
2x = 16
x = 8

3. $\frac{x+1}{3}+\frac{x+2}{7} = 2$ multiply by 3 and 7

$7(x+1) + 3(x+2) = 3(7)(2)$

$7x + 7 + 3x + 6 = 42$

$10x = 42 - 13$

$x = \frac{29}{10}$