Question

Se 2x/5+15x-1/20=1/3 então o valor de 3x+1 é:
A) 1
B) 2
C) 3
D) 4

Answer 1

Olá,

2x/5 + (15x-1)/20 = 1/3
(8x+15x-1)/20 = 1/3
(23x-1)/20 = 1/3
23x-1 = 20·1/3
23x-1 = 20/3
23x = 20/3+1
23x = (20+3)/3
23x = 23/3
x = 23/(3·23)
x = 1/3

Logo, vamos ter 3x+1 = 3(1/3)+1 = 3/3+1 = 1+1 = 2

Resposta: b) 2