The lengths, in cm, of the sides of a triangle are 2x+72x + 72x+7, 3x−43x - 43x−4 and x+3x + 3x+3

Write down an expression, in terms of xxx, for the perimeter of the triangle.
The perimeter of the triangle is 54 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.