The lengths, in cm, of the sides of a triangle are 3x−53x - 53x−5, 2x−12x - 12x−1 and x+1x + 1x+1

Write down an expression, in terms of xxx, for the perimeter of the triangle.
The perimeter of the triangle is 31 cm. Work out 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.