Question

Sistema de equações

A) x-2y=18
x+4y=6

B) x=y-2
2x=y-1

C) 5x-y=0
5x+2y=3

Answer 1

a)x-2y=18(-1)
x+4y=6

-x+2y=-18
x+4y=6
6y=-12
y=-2

x+4y=6
x+4(-2)=6
x-8=6
x=14

b)x=y-2(-1)
2x=y-1
-x=-y+2
2x=y-1
x=+1

x=y-2
1=y-2
y=+3

c)5x-y=0(-1)
5x+2y=3
-5x+y=0
5x+2y=3
+3y=3
y=1

5x-y=0
5x-(1)=0
5x-1=0
5x=+1
x=1/5 ou 0,2