2000x4+1995+2001x1995/1995x495+1995x5+1995x3
Tính A= \(\frac{\left(2000x4+1995+2001x1995\right)}{\left(1995x495+1995x5+1995x3\right)}\)
A.\(\frac{2004x2005+2006x6-6}{2005x1997+4x2005}\) \(\frac{1999x2000+2001x5-5}{504x2000+500x2000}\)
B.\(\frac{2003x4+1998+2001x2002}{2002+2002x502+500x2002}\) \(\frac{2000x4+1995+2001x1995}{1995x495+1995x5+1995x3}\)
C.\(\frac{72:2x574+286x2x64}{4+4+8+12+20+...+220}\) \(\frac{72+36x2+24x3+18x4+12x6+168}{2+2+4+6+...+512+1024}\)
2000x4=?
19246x8=?
làm đc câu này là sư phụ
2000x4=8000
19246x8=153968
2000 x 4 = 8000
19246 x 8 = 153968
tk cho mình nha
Cho (C) : y = 2018 x - 2000 x 4 + 1 . Tìm tiệm cận ngang của (C).
B=1995+1995+...+1995-19950
10 số 1995
B = 1995 x 10 -19950 = 19950 - 19950 = 0
\(B=1995+1995+...+1995-19950\)
10 số 1995
\(=1995\times10-19950\)
\(=19950-19950\)
\(=0\)
Chúc em học tốt!
Tính nhanh
98 x 1995 + 1995 + 1995
CM rằng nếu x2+y2+z2/a2+b2+c2=x2/a2+y2/b2+z2/c2 thì
x1995+y1995+z1995/a1995+b1995+c1995=x1995/a1995+y1995/b1995+z1995/c1995
giúp mk nốt pài này nha
Tinh
1995*1996-1000/1995*1995+995
1995x1996-1000:1995x1995+995=3982015
Robert Lewandowski ban giai ra giup mk duoc ko
Cho \(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}=\frac{1}{a+b+c}\)
Chứng minh \(\frac{1}{a^{1995}}+\frac{1}{b^{1995}}+\frac{1}{c^{1995}}=\frac{1}{a^{1995}+b^{1995}+c^{1995}}\)
Ta có : 1/a+1/b+1/c=1/a+b+c
suy ra:(ab+bc+ac)/abc=1/a+b+c
=>(ab+ac+bc)(a+b+c)=abc
=>a2b+ab2+a2c+ac2+b2c+bc2+3abc=abc
(a+b)(b+c)(a+c)=0
=>a=-b hc b=-c hc a=-c
ta sẽ dễ dàng c/m được với 3 t/h trên thì 1/a1995+1/b1995+1/c1995=1/a1995+b1995+c1995
Cho \(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=\dfrac{1}{a+b+c}\) .CMR:
\(\dfrac{1}{a^{1995}}+\dfrac{1}{b^{1995}}+\dfrac{1}{c^{1995}}=\dfrac{1}{a^{1995}+b^{1995}+c^{1995}}\)
HELP ME !
Xuất phát từ giả thiết , ta có :
\(\dfrac{1}{a}+\dfrac{1}{b}+\dfrac{1}{c}=\dfrac{1}{a+b+c}\)
=> \(\dfrac{bc+ac+ab}{abc}=\dfrac{1}{a+b+c}\)
=> \(\left(a+b+c\right)\left(ab+bc+ac\right)=abc\)
=> \(\left(a+b+c\right)\left(ab+bc+ac\right)-abc=0\)
=> \(a\left(ab+bc+ac\right)+b\left(ab+bc+ac\right)+c\left(ab+bc+ac\right)-abc=0\)=> a2b + abc + a2c + ab2 + b2c + abc + abc + bc2 + ac2 - abc = 0
=> ab(a + b) + ac( a + c) + bc( b + c) + 2abc = 0
=> ab( a + b + c) + ac( a + b + c ) + bc( b + c) = 0
=> ( a + b + c)a( b + c) + bc( b + c) = 0
=> ( b + c)( a2 + ab + ac + bc) = 0
=> ( b + c)( a + b)( c + a) = 0
Suy ra :
* b = -c
*a = -b
* c = -a
TH1 :Với b = -c
\(VT=\dfrac{1}{a^{1995}}+\dfrac{1}{\left(-c\right)^{1995}}+\dfrac{1}{c^{1995}}=\dfrac{1}{a^{1995}}\)
\(VP=\dfrac{1}{a^{1995}+b^{1995}+c^{1995}}=\dfrac{1}{a^{1995}+\left(-c\right)^{1995}+c^{1995}}=\dfrac{1}{a^{1995}}=VT\)
TH2 : với a = -b
\(VT=\dfrac{1}{\left(-b\right)^{1995}}+\dfrac{1}{b^{1995}}+\dfrac{1}{c^{1995}}=\dfrac{1}{c^{1995}}\)
\(VP=\dfrac{1}{a^{1995}+b^{1995}+c^{1995}}=\dfrac{1}{\left(-b\right)^{1995}+b^{1995}+c^{1995}}=\dfrac{1}{c^{1995}}=VT\)
TH3 . c = -a , Tương tự
Vậy , đẳng thức được Chứng minh