# gr.10 math

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solve the linear system using substitution. please show me the steps!:)

x-y=-5
2x-y=-7

• gr.10 math -

arrange the first equation to x = y-5

sub replace the x in the second equation with that expression

2x-y=-7
2(y-5) - y = -7
2y - 10 - y = -7
y = -7 + 10
y = 3 , now let's put that back into x = y-5
x = 3 - 5
x = -2

so x = -2, y = 3

check in the first:
is -2 - (3) = -5 ? , yes!
in the second:
is 2(-2) - (3) = -7 ? , yes!

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