Question

resolva os sistemas de equacoes: a) }x+y=9 b) }3x-y=4
}x-y=7 }x+y=2

Answer 1

a)x+y=9
x=9-y
9-y-y=7
-y-y=7-9
-2y=-2
2y=2
y=2
2
y=1

b)x+y=2
x=2-y
3 (2-y)-y=4
6-y-y=4
-y-y=4-6
-2y=-2
2y=2
y=2
2
y=1