Question

Determine um número real ''a'' para que as expressões (3a + 6)/8 e (2a + 10)/6 sejam iguais.

Answer 1

$\dfrac{3a+6}{8}=\dfrac{2a+10}{6}\\\\\\\dfrac{3a+6}{8}=\dfrac{2(a+5)}{2.3}\\\\\\\dfrac{3a+6}{8}=\dfrac{a+5}{3}$

Multiplicando em cruz:

$3(3a+6)=8(a+5)\\9a+18=8a+40\\8a-8a=40-18\\a=22$