Answer:
Explanation:
We first solve for y in the second equation.
The second equation is
[tex]-7x-14=7y[/tex]dividing both sides by 7 gives
[tex]\frac{-7x-14}{7}=y[/tex][tex]-x-2=y[/tex]We now substitute the value of y into the first equation.
The first equation is
[tex]10=-10x-5y[/tex]substituting the value of y gives
[tex]10=-10x-5(-x-2)[/tex]Simplifying the right-hand side gives
[tex]10=-10x+5x+10[/tex][tex]10=-5x+10[/tex]Subtracting 10 from both sides gives
[tex]\begin{gathered} -5x=0 \\ \boxed{x=0} \end{gathered}[/tex]With the value of x in hand, we now put it into -7x - 14 = 7y to get
[tex]-7(0)-14=7y[/tex][tex]-14=7y[/tex]Dividing both sides by 7 gives
[tex]\boxed{y=-2.}[/tex]Hence, to conclude, the solution to the system is
x = 0
y = -2.
Therefore, x + y = -2
