How would I differentiate something in the form of (ax+b)^n

To tackle this type of question you would need to differentiate by substitution by implying the chain rule.If we substitute ax+b for a single character,lets say q , the expression becomes q^n which is easier to differentiate,we now differentiate this and differentiate the substituted ax+b.We now multiply this together to get the derivative. We multiply the terms toghether because the chain rule states ,dy/dx=(dy/dq)*(dq/dx)