Solve this simultaneous equations, clearly showing all of your workings: x^2 + 2y =9, y - x = 3
Equation 1: x2 + 2y = 9Equation 2: y - x = 3
Rearrange equation 2: y = 3 + x
Substitute y = 3 + x into equation 1x2 + 2(3 + x) = 9x2 + 6 + 2x = 9x2 + 2x - 3 = 0(x + 3)(x - 1) = 0so x = 1 and -3
substitute x = 1 into rearranged equation 2y = 3 + 1y = 4
substitute x = -3 into rearranged equation 2y = 3 - 3y = 0
So when x = -3, y= 0and when x = 1, y = 4
EJ
Related Maths GCSE answers
All answers ▸When do I use Sin, Cos or Tan?
Solving quadratic equations using the factorisation method.
A conical vase of base radius 5cm and height 20cm is filled with 200ml of water, how high is the water level? Give your answer to 3 significant figures.
Solve the following simultaneous equations. x^2 + 2y = 9, y = x + 3