There are three ways to solve systems of linear equations in two variables:
graphing.
substitution method.
elimination method.
1.
2x+y=15x−y=9
a.
(8,−1)
b.
2x+y=15x−y=9
2x+x−9=15y=x−9
3x=24y=x−9
x=8y=−1(8,−1)
c.
2x+y=15x−y=9
3x−2y=122x+5y=72
2x+y+x−y=15+9x−y=9
3x=24x−y=9
x=88−y=9x=8y=−1(8,−1)
2.
3x−2y=122x+5y=7
a.
(1974,−193)
b.
3x−2y=122x+5y=7
y=23x−62x+5(23x−6)=7
y=23x−6219x=37
x=1974y=23(1974)−6x=1974y=−193(1974,−193)
c.
3x−2y=122x+5y=7
6x−4y=246x+15y=21
6x+15y−(6x−4y)=21−243x−2y=12
19y=−3x=32y+4
x=1974y=−193(1974,−193)
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