How do you solve the system x+6y=-22x+6y=−22 and -6x-2y=-4−6x−2y=−4 by substitution?

1 Answer
Don't Memorise
Jun 10, 2015

The solution for the system of equations is
color(red)(x = 2 , y=-4x=2,y=−4

Explanation:

x+6y=-22x+6y=−22
x=color(red)(-22 - 6yx=−22−6y ..................equation (1)(1)
-6x-2y=-4−6x−2y=−4 ............equation (2)(2)

Substituting equation (1)(1) in equation (2)(2) to find yy

-6x-2y=-4−6x−2y=−4
-6color(red)((-22 -6y))-2y=-4−6(−22−6y)−2y=−4
132 +36y -2y =-4 132+36y−2y=−4
132 +34y=-4 132+34y=−4
34y=-136 34y=−136
color(red)(y=-4y=−4

Substituting yy in equation 11 to find xx
x = -22 - 6yx=−22−6y
x = -22 -6.(-4)x=−22−6.(−4)
x = -22+24x=−22+24
color(red)(x = 2x=2

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