Question

12 . (x - 1) : 3 = 72

Answer 1

\(12\left(x-1\right)=72.3\\ 12\left(x-1\right)=216\\ \left(x-1\right)=216:12\\ x-1=18\\ x=18+1\\ x=19\)

Answer 2

12.(x-1):3=72
\(\Rightarrow\)12(x-1)=72.3
\(\Rightarrow\)12(x-1)=216
\(\Rightarrow\)x-1=216:12
\(\Rightarrow\)x-1=18
\(\Rightarrow\)x=19

Answer 3

\(12\left(x-1\right)=72\times3\)

\(12\left(x-1\right)=216\)

\(x-1=216:12\)

\(x-1=18\)

\(x=19\)