Question

Resolva os sistemas abaixo
A) 2x+y=10
X- y= 2

B) 2x+y=10
. 2x+2y=2

C) x+y=15
. 2x+3y= -3

Answer 1

Ok vamos lá.

a) 2x+y=10
x-y=2
3x=12
x=4 
x-y=2
4-y=2
-y=2-4
y=2

b) 2x+y=10   <-- y=10-2x
2x+2y=2
2x+2(10-2x)=2
2x+20-4x=2
2x-4x=2-20
-2x=-18
x=9
y=10-2x
y=10-2(9)
y=10-18
y=-8

c) x+y=15  x=15-y
2x+3y=-3
2(15-y)+3y=-3
30-2y+3y=-3
y+30=-3
y=-3-30
y=-33
x=15-y
x=15-(-33)
x=48
 
Prontinho (^^)