Week 7 – Precalculus 11 – Completing the square

x squared + 8x + 2 =22 (example)

we divide 8 by 2 and then square it, so that becomes 4 squared and then 16. After that we use a zero pair so 16 – 16, so that means x squared + 8x + 16 – 16 +2 = 22. x squared + 8x +16 equals to (x+4) squared. (x+4) squared – 14 = 22. (x+4) squared = 36. Take the roots of both sides, that leaves (x+4) = root 36. x+4 equals +-6. X1 = -10, X2 = 2.

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