i don't know how to do this i need someone to explain me how to do it?

Question

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

Answer 1

-3(2x-5) + (2/3)(x+5)  = 7

 

-6x + 15 + (2/3)X + 10/3 =  7   <--- distributive;  watch the negative signs!!!!

 

-18X + 45 + 2X + 10 = 21  <---- multiplies everything by 3 to clear the fractions

 

-16X + 55 = 21  <--- combines like terms

 

-16X = 21 - 55

 

-16X = -34

 

X = -34/-16 = 17/8

 

CHECK:

 

-3(  2(17/8) - 5) + (2/3) ( 17/8 + 5) =

 

-3 ( 34/8 - 5) + (2/3) ( 17/8 + 5 ) =   

 

-3 ( 34/8 - 40/8 ) + (2/3) ( 17/8 + 40/8) = <---- common denominators

 

-3 ( -6/8) + (2/3) ( 57/8)

 

18/8 + 114/24

 

54/24 + 114/24

 

168/24

 

= 7