Question

calcule os sistemas

A) x+y=10
x-y=6

B) x•y=10
x-y=3

C) x+y=12
x÷y=2

D) y=2x
x-y=0

Answer 1

a) x= 10-y
(10-y)-y = 6
-2y+10= 6
2y= 10-6
y= 4/2
y=2
substituir na primeira
x= 10-y => x = 10-2=> x= 8

b)x=3+y
(3+y).y = 10
y^2 + 3y -10 = 0
y= 5 e y= -2
substituir
x= 3+5 => x = 8
x= 3 -2 => x = 1

c)x= 12-y
(12-y)/y = 2
12-y = 2y
3y = 12
y=4
substituir
x= 12 -4 =>x = 8

d)y= 2x
x-2x = 0
x=0
y=2.0 =0

Bons estudos..