Question

A raiz da equação $3(a-4x)+7(2x-a)-5(3x+2a)+a=0$ é:
a)a
b)-a
c)0
d)2a
e)-2a

Answer 1

Explicação passo-a-passo:

$\sf 3\cdot(a-4x)+7\cdot(2x-a)-5\cdot(3x+2a)+a=0$

$\sf 3a-12x+14x-7a-15x-10a+a=0$

$\sf -12x+14x-15x+3a-7a-10a+a=0$

$\sf 2x-15x-4a-9a=0$

$\sf -13x-13a=0$

$\sf -13x=13a~~~\cdot(-1)$

$\sf 13x=-13a$

$\sf x=\dfrac{-13a}{13}$

$\sf \red{x=-a}$

Letra B