Use PEDMAS.
Notice that Division and Multiplication can be done in 1 step together. Same as Addition and Subtraction.
\(18+36\div 3+(9-6)^2\)
\(=18+36\div 3 + 3^2\)P(arentheses)
\(=18+36\div 3 + 9\)E(xponents)
\(=18+12+9\)D(ivision) and M(ultiplication)
\(=39\)A(ddition) and S(ubtraction)