Answers

2014-06-28T21:26:25+08:00
4x²-20 = 11
x²-5 = 11/4
x²-5+25/4 = 11/4 + 25/4
(x-5/2)² = 36/4
√(x-5/2)² =√36/4
x-5/4 = +-6/4

x-5/4 = 6/4
x = 11/4

x-5/4 = -6/4
x = -1/4
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