Q1 of 227 Page 105

Solve the following quadratic equations by completing the square.

x2 + 6x –7 = 0

x2 + 6x – 7 = 0


= x2 + 6x = 7


Add 9 on both sides


= x2 + 6x + 9 = 7 + 9


= x2 + 2(3)(x) + 32 = 16


= (x + 3)2 = 16


= x + 3 = √16


= x + 3 = ± 4


x + 3 = 4 or x + 3 = –4


x = 4 – 3 or x = – 4 – 3


x = 1 or x = – 7


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