Question

Resolva os sistemas

a) x+2y=6
2x-y=10

b) x-3y=9
5x-2y=12

Answer 1

a) x=6-2y

2(6-2y)-y=10
12-4y-y=10
-5y=10-12
y=-2/-5
y=2/5

x=6-2y
x=6-2(2/5)
x=6-4/5
x=(30/5)-(4/5)
x=26/5

b) x=9+3y

5(9+3y)-2y=12
45+15y-2y=12
13y=12-45
y=-33/13

x=9+3y
x=9+3(-33/13)
x=9-(99/13)
x=(117/13)-(99/13)
x=18/13