Question

resolvar os sitesma
a) x+y=128
x-y=8


b)X+y=52
x-y=28

c) x+y=132
x-y=8

d)x+y=125
x-y=15

Answer 1

a) y= 128 - x

x - (128-x) = 8
x - 128 + x = 8
x + x = 128 + 8
2x = 136
x = 136/2
x = 68

y = 128 - x
y = 128 - 68
y = 60


b) y = 52 - x

x - (52 - x) = 28
x - 52 + x = 28
x + x = 28 + 52
2x = 80
x = 80/2
x = 40

y = 52 - x
y = 52 - 40
y = 12


c) y = 132 - x

x - (132 - x) = 8
x - 132 + x = 8
x + x = 8 + 132
2x = 140
x = 140/2
x = 70

y = 132 - x
y = 132 - 70
y = 62


d) y = 125 - x

x - (125 - x) = 15
x - 125 + x = 15
x + x = 15 + 125
2x = 140
x = 140/2
x = 70

y = 125 - x
y = 125 - 70
y = 55