-4x+4 over 7+2x-5 over 7=3 over 7

Question

this question was on a math test I took today, that I got back but I don't get it. oh and when it says 4 over 7 that means a fraction. please help :)

Answer 1

So, Brianna, when you have everything over the same denominator, you can disregard the denominator!

 

-4x + 4 + 2x - 5 = 3

-2x - 1 = 3

- 2x = 4

x = -2

 

Let's check...

 

(-4(-2) + 4)/7 + (2(-2) - 5)/7 = 3/7

(8+4)7 + (-4 - 5) = 3/7

12/7 - 9/7 = 3/7

3/7 = 3/7

 

Boom.