Question

Resolva as incompletas 7x²-84x=0

Answer 1

7x²-84x=0
7x·(x-12)=0
x·(x-12)=0
x=0
x=12

Answer 2

$7x^2-84=0 \\ \\ fatorar~~sendo~~x~~fator~~comum~~em~~evid\hat{e}ncia \\ \\ x(7x-84)=0 \\ \\ 7x-84=0~~~~e~~~x=0 \\ 7x=84 \\ x=84\div7 \\ x=12 \\ \\ S=\{0,12\}$