Answers

2014-06-26T18:29:39+08:00
4x²-20=11
4x²-20+25=36
(2x-10)²=36
2x-10=+or-√36
2x-10=+or-6
2x=10+or-6
solutions are
2x=10+(-6)
2x=10-6
2x=4
x=2
the second solution is
2x=10+6
2x=16
x=8

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