1.: solve 1/2x^2 + 4x - 2/3 = 0 by completing the square.
2.: solve (x-1) (2+3x) = x^2 by completing the square.
(Leave your ans in surd form if neccessary.)
##### 請with steps...(盡量唔好跳step....)
唔該曬.....
2 條中4 maths
2007-09-15 1:03 am
回答 (2)
2007-09-15 1:21 am
✔ 最佳答案
1/2x^2 + 4x - 2/3 = 03x^2 + 24x - 4 = 0
x=(-24+(24^2-4x3x(-4))^1/2)/(2x3)
=(-24+(572+48)^1/2)/6
=(-24+25)/6
=1/6 and
x=(-24-(24^2-4x3x(-4))^1/2)/(2x3)
=(-24-(572+48)^1/2)/6
=(-24-25)/6
=-8.2
(x-1) (2+3x) = x^2
2x+3x^2-2-3x=x^2
2x^2-x-2=0
x=(1+(1^2-4x2x(-2))^1/2)/(2x4) and
x=(1-(1^2-4x2x(-2))^1/2)/(2x4)
try it by yourself!!
2007-09-15 1:29 am
1) 1/2X*X+4X=2/3
1/2X*X=2/3/4X
1/2X=2/12X/X
1/2X=1/6
X=1/6*2
X=2/6
X=1/3
2) 2X-2+3X^2-3X=x^2
2X-3X+3X^2-X^2=2
2X^2-X=2
X(2X-1)=2
give up!第2題唔識
1/2X*X=2/3/4X
1/2X=2/12X/X
1/2X=1/6
X=1/6*2
X=2/6
X=1/3
2) 2X-2+3X^2-3X=x^2
2X-3X+3X^2-X^2=2
2X^2-X=2
X(2X-1)=2
give up!第2題唔識
收錄日期: 2021-04-13 18:34:12
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https://hk.answers.yahoo.com/question/index?qid=20070914000051KK01883