Question

resolva os sistemas com calculo a seguir
a)x+2y=5
x+3y=8
b)x+y=10
x-y=6
c)3x+y=17
x-y=7
d)x+y=6
2y-y=24
e)2x-y=0
x-3y=5

Answer 1

a)x+2y=5 (-1)
x+3y=8  
-x-2y=-5
 x+3y=8

y=3
x+2.3=5
x+6=5
x=5-6
x=-1
b)x+y=10
x-y=6 

2x=16
 x=8

8-y=6
-y=6-8
-y=-2 (-1)
 y=2
c)3x+y=17
x-y=7

4x=24
 x=6
d)x+y=6
2y-y=24

x+y=6
y=24

x+24=6
x=6-24
x=-18
e)2x-y=0
x-3y=5 (-2)

2x-y=0
-2x+6y=-10

5y=-10
 y=-2

2x-(-2)=0
2x+2=0
2x=2
  x=1