Question

resolva os sistemas pelo método da adição


a) x-y=5
x+y=7


b)x=y+4
x+y=20



c)x-y=6
x+y=-7

D)x+2y=7
x_2y=-5​

Answer 1

Resposta:

a) x-y=5 x-y=5

x+y=7 6-y=5

-y=5-6

2x=12 y=1

x=12/2

x=6

b) x-y=4 x+y=4

x+y=20 12+y=4

y=4+12

2x=24 y=16

x=24/2

x=12

c) x-y=6 x-y=6

x+y=-7 -1/2-y=6

-y=6+1/2

2x=-1 -y=7/2 +1/2

x=-1/2 y=-8/2

y=-4

d)x+2y=7 x+2y=7

x-2y=-5 1+2y=7

2y=7-1

2x=2 2y=6

x=2/2 y=6/2

x=1 y=3