1.Solve the following equations by the method of completing the square.
a) x^2 - 8x = 0
b) x^2 + 10x = -16
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2007-11-04 9:25 pm
回答 (1)
2007-11-04 9:37 pm
✔ 最佳答案
1a) x^2 - 8x = 0x^2-8x+16-16=0
(x-4)^2=16
(x-4)=+/-4
x-4=4 or x-4=-4
x=8 or x=0
1b) x^2 + 10x = -16
x^2+10x+16=0
x^2+10x+25+16-25=0
(x+5)^2-9=0
(x+5)^2=9
x+5=3 or x+5=-3
x=-2 or x=-8
2007-11-04 13:39:42 補充：
1a) can use other method too. x^2-8x=0 x(x-8)=0 (x-0)(x-8)=0 x=0 or x=8
收錄日期: 2021-04-13 21:13:17
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