A variable needs to be eliminated to solve the system of equation below. Choose the correct first step. 3x-9y=-39. 3x-6y=-21

3

−

9

=

−

3

9

3

−

6

=

-21

Step-by-step explanation:

3x−9y=−39, 3x−6y=−21 : x=5, y=6

Steps

[ 3x−9y=−393x−6y=−21 ]

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Isolate x for 3x−9y=−39: x=−13+3y

Substitute x=−13+3y

[ 3(−13+3y)−6y=−21 ]

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Simplify

[ −39+3y=−21 ]

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Isolate y for −39+3y=−21: y=6

For x=−13+3y

Substitute y=6

x=−13+3· 6

Simplify

x=5

The solutions to the system of equations are:

answer: b.

step-by-step explanation:

the y coordinate for point b is 0, and answer b is the only one with that y coordinate.

step-by-step explanation: