A rectangle has a length of (4x−3)(4x - 3)(4x−3) cm and a width of (x+6)(x + 6)(x+6) cm.

Find an expression for the perimeter of the rectangle.
Given the rectangle has a perimeter of 31 cm, find the value of xxx.
71 exam-style questions on Edexcel GCSE Maths Forming and Solving Equations. Each one has a worked solution and a mark scheme showing where the marks go.