GCSE Maths

Factorising Quadratics

Here are worked solutions to the problems on the previous page.
  1. x² + 7x + 10 = 0.
    10 = 2 × 5 and 2 + 5 = 7 so:
    (x + 2)(x + 5) = 0
    Solutions: x=-2 and x=-5
  2. x² + x - 30 = 0.
    -30 = -5 × 6 and -5 + 6 = 1 so:
    (x + 6)(x - 5) = 0
    Solutions: x=-6 and x=5
  3. x² - 10x - 24 = 0.
    -24 = -12 × 2 and -12 + 2 = -10 so:
    (x - 12)(x + 2) = 0
    Solutions: x=12 and x=-2

If you got one or more right: very well done! This is not easy. If you got any wrong, make sure you can see why.

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