Question

calcule o valor de y​

Answer 1

Resposta:

$\left \{ {{x/5 + y/2 = 3/5} \atop {y -x = 4}} \right.$

y - x = 4

y = 4 + x

x/5 + y/2 = 3/5

2x + 5y/10 = 3/5

2x + 5(4+x)/10 = 3/5

2x + 20 +5x = 30/5

7x = 6 - 20

7x = -14

x = -2

y = 4 + x = 4 -2 = 2