Solve the quadratic equation: x^2 - 2x - 15 = 0
We need to find numbers that multiply together to give -15. This could be -1 and 15, 1 and -15, -3 and 5, 3 and -5. The numbers we need must add up to -2 as well (from -2x term). Therefore our set must be 3 and -5.
So we get (x+3)(x-5)=0 with x=-3 and x=5
SK
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