能不能用配方法解方程 24(R)(1-R)=6

2007-01-01 4:06 am
能不能用-配方法-解方程24(R)(1-R)=6

24(R)(1-R)=6

回答 (5)

2007-01-01 4:19 am
✔ 最佳答案
24(R)(1-R)=6
(R)(1-R)=1/4
R^2-R=-1/4
R^2-R+(1/2)^2=-1/4+(1/2)^2
(R+1/2)^2=0
R=-1/2(repeated)

不知道會不會錯~
但以我所知,所有二元一次方程式都可以用配方法解,
所以才會有quadratic formula

2006-12-31 20:30:18 補充:
不好意思~其實R=1/2......我搞錯左負號.....
2007-01-01 4:14 am
24(R)(1-R)=6
24R(1-R) = 6
24R*1 - 24R^2 = 6
-24R^2 + 24R -6= 0
24R^2 -24R+6 = 0 <-- all divided by 6
4R^2-4R+1 = 0
(2R - 1)(2R-1)= 0
--> 2R-1=0
2R =1
R= 1/2 (REPEATED)
2007-01-01 4:13 am
24(R)(1-R)=6
24R^2-24R+6=0
24( R^2 - R + 1/4 )
24( R- 1/2 )^2
2007-01-01 4:12 am
yes you can

24R(1-R)=6

4R(1-R)=1

-4R^2+4R=1

-4R^2+4R-1=0

R=(-4±√(4^2-4(-4)(-1)))/2(-4)

R=(-4±√0)/(-8)

R=1/2

2006-12-31 20:13:27 補充:
任何二次方程都可以用配方法解求解公式都係咁黎
參考: me
2007-01-01 4:11 am
R-R^2=1/4
R^2-R+1/4=0
(2R-1)^2=0
R=1/2


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