Respuesta :

3x-5x+8x+x=42
-2x+8x+x=42
6x+x=42
7x=42
x=42/7
x=6
What we have to do here is group our x's together. 
So just add all the x's together...
3x - 5x + 8x + 1x = 7x 

Now.. we can write 7x instead of all of that
7x = 42 Now divide both sides by 7 
÷7 = ÷7  Now it cancels out on the left side And we solve for the right side. 
**********
x = 42 ÷ 7 = 6 
x = 6 

Good Luck! :)