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Solve this system using the substitution method 10 = -10x-5y. -7x-14 = 7y What is x+y

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Answer:

Explanation:

We first solve for y in the second equation.

The second equation is


-7x-14=7y

dividing both sides by 7 gives


(-7x-14)/(7)=y
-x-2=y

We now substitute the value of y into the first equation.

The first equation is


10=-10x-5y

substituting the value of y gives


10=-10x-5(-x-2)

Simplifying the right-hand side gives


10=-10x+5x+10
10=-5x+10

Subtracting 10 from both sides gives


\begin{gathered} -5x=0 \\ \boxed{x=0} \end{gathered}

With the value of x in hand, we now put it into -7x - 14 = 7y to get


-7(0)-14=7y
-14=7y

Dividing both sides by 7 gives


\boxed{y=-2.}

Hence, to conclude, the solution to the system is

x = 0

y = -2.

Therefore, x + y = -2

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