Answers

2014-02-19T16:38:00+08:00
X²-8x=5
x²-8x+__=5
focus in 8x or b.To solve it easily divide your "b" in 2 or use this formula (b/a)² to simplify
x²-8x+16=5 if you add constant or a variable in other side, you suppose to add to the other side to make it balance.
x²-8x+16=5+16
x²-8x+16=21
(x-4)²=21 or a(h,k)²=0 okay^^
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