Question

2x - 5 = y - 4
7x - y = y + 4​

Answer 1

Resposta:

(I) x = (y+1)/2 ---> x = (-1/3 +1)/2 ---> x = 2/3

Explicação passo-a-passo:

2x-5=y-4 -->2x=y+1 ---> x = (y+1)/2 (I)   { 7x-y=y+3 -->7x=2y+3--> x = (2y+3)/7 (II)           (I) = (II) --> (y+1)/2 = (2y+3)/7 ---mmc(2,7) = 14

..................  7y + 7 = 4y + 6

................... 7y - 4y = -1 ---> 3y = -1 ---> y = - 1/3

(I) x = (y+1)/2 ---> x = (-1/3 +1)/2 ---> x = 2/3