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Solve the system of equations using substitution. y = -7x 2x – y = -9

User Dean L
by
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1 Answer

4 votes

Answer:

x = -1

y = 7

Explanation:

We have a system of equations and are asked to solve using substitution.

y = -7x

2x - y = -9

Since we have an equation for y by itself, we can plug the first equation into the second.

2x - (-7x) = -9

Distribute :

(-(-7x))

2x + 7x = -9

Add like terms :

9x = -9

Divide 9 by both sides to get x :

x = -1

Now that we know x, we can plug it into the first equation to find y :

y = -7(-1)

y = 7

User Egoldx
by
6.9k points