Question

resolva usando o metado da comparação
2x-y=1
2x+3y=21

Answer 1

2x-y = 1 (.-1)
-2x+y = -1
y = 2x-1

2x+3y = 21
2x + 3(2x-1) = 21
2x + 6x -3 = 21
8x = 21+3
8x = 24
x = 24/3
x = 8

2x - y = 1
2.8 - y = 1
16 - y = 1
- y = 1-16
-y = -15 (.-1)
y = 15

S = (8,15)