Question

me ajudem a resolve 6.(a-1)=12

Answer 1

6.(a-1)=12
6a-6=12
6a=12+6
6a=18
a=18/6
a=3

Answer 2

$6.(a-1)=12\to \\\\ 6a-6=12\to \\\\ 6a=12+6\to \\\\ 6a=18\to \\\\ a= \dfrac{18}{6} \to \\\\ \boxed{a=3}$