Question

4-Encontre os valores das incógnitas 2x + y = 5 x - y = 1​

Answer 1

I. 2x + y = 5

II. 5x - y = 1

I + II. 2x + y + 5x - y = 5 + 1

I + II. 7x  = 6

I + II. x = 6/7

I. 2 . 6/7 + y = 5

I. y + 12/7 = 5

I. y = 5 - 12/7

I. y = (35 - 12)/7

I. y = 23/7

Resposta: x = 6/7 e y = 23/7