Answer:
x=2
Step-by-step explanation:
We see that there is already a common variable that can be canceled out -- y. y+(-y)=0! (Alternatively you may also multiply an equation by negative 1 and do subtraction, but in this case it's already done for you)
So now we just do some addition.
2x+6x=8x
y+(-y)=0
7+9=16
This means that 8x=16. Now we solve!
(Divide both sides by 8)
We're left with x=2 :)
