Question

resolução algiebrica do sistema {2x+y=7 x+y=y

Answer 1

2x + y = 7
x + y = y

2x + y = 7
y = 7 - 2x

x + y = y
x + 7 - 2x = 7 - 2x
x - 2x + 2x = 7 - 7
x = 0

y = 7 - 2x
y = 7 - 2.0
y = 7 - 0 = 7

Answer 2

2x + y = 7
x + y = y

x  + y - y = 0
x = 0

2x + y = 7
2.0 + y = 7
0 + y = 7
y = 7