Các câu hỏi tương tự
Chứng minh nếu a/b=c/d thì 12a^2+7a.b/ 20a^2 - 13b^2= 12c^2+7c.d/ 20c^2-13d^2.
chung minh rằng :Neu a phan b = c phan d thi 5a2 +2ab phan 10a2 - 3b2=5c2+2cd phan 10c2 -3d2
(gia thiet cac ti so deu co nghia)
Cm : Neu a/b=c/d thi 2014a+2015b/2014a-2015b=2014c+2015d/2014c-2015d gia thiet cac ti so deu co nghia
Cho a.b,c la 3 so khac 0 thoa man : ab + a + b / a + b = bc + b + c / b + c = ca + c + a/ c + a ( voi gia thiet cac ti so deu co nghia)
Tinh gia tri bieu thuc M = ab+bc+ca+2017/ a^2 + b^2 + c^2 + 2017
cac ban giai giup minh bai tap nay khan cap nhe:
cho cac so a,b,c la ba so nguyen khac 0, thoa man: ab/(a+b)=bc/(b+c)=ac/(a+c) ( gia thiet cac ti le thuc deu co nghia). tinh M= (ab + bc + ca)/(a^2+b^2+c^2)
xin cam on rat nhieu
\(Cho\frac{a}{b}=\frac{c}{d}.CMR:\frac{5a^2+7ab}{4a^2-9b^2}=\frac{5c^2+7cd}{4c^2-9cd}\)
Cho tỉ lệ thức : \(\frac{a}{b}=\frac{c}{d}\)chứng tỏ rằng :\(\frac{3a^2+5b^2}{3c^2+5d^2}=\frac{2a^2+7ab}{2c^2+7cd}\)
a,Cho \(\frac{2bz-3cy}{a}=\frac{3cx-az}{2b}=\frac{ay-2bx}{3c}CMR:\frac{x}{a}=\frac{y}{2b}=\frac{z}{3c}\)
b, CHO \(\frac{b+c}{bc}=\frac{2}{a}CMR:\frac{b}{c}=\frac{a-b}{c-a}\)( cac ti so deu co nghia)
Cho frac{a}{b}frac{c}{d}. Chứng minh:a) frac{left(a-bright)^3}{left(c-dright)^3}frac{3a^2+2b^2}{3c^2+2d^2}b)frac{4a^4+5b^4}{4c^4+5d^4}frac{a^2b^2}{c^2d^2}c)left(frac{a-b}{c-d}right)^{2005}frac{2a^{2005}-b^{2005}}{2c^{2005}-d^{2005}}d)frac{2a^{2005}+5b^{2005}}{2c^{2005}+5d^{2005}}frac{left(a+bright)^{2005}}{left(c+dright)^{2005}}e)frac{left(20a^{2006}+11b^{2006}right)^{2007}}{left(20a^{2007}-11b^{2007}right)^{2006}}frac{left(20c^{2006}+11d^{2006}right)^{2007}}{left(20c^{2007}-11d^{2007}right)^{20...
Đọc tiếp
Cho \(\frac{a}{b}=\frac{c}{d}\). Chứng minh:
a) \(\frac{\left(a-b\right)^3}{\left(c-d\right)^3}=\frac{3a^2+2b^2}{3c^2+2d^2}\)
b)\(\frac{4a^4+5b^4}{4c^4+5d^4}=\frac{a^2b^2}{c^2d^2}\)
c)\(\left(\frac{a-b}{c-d}\right)^{2005}=\frac{2a^{2005}-b^{2005}}{2c^{2005}-d^{2005}}\)
d)\(\frac{2a^{2005}+5b^{2005}}{2c^{2005}+5d^{2005}}=\frac{\left(a+b\right)^{2005}}{\left(c+d\right)^{2005}}\)
e)\(\frac{\left(20a^{2006}+11b^{2006}\right)^{2007}}{\left(20a^{2007}-11b^{2007}\right)^{2006}}=\frac{\left(20c^{2006}+11d^{2006}\right)^{2007}}{\left(20c^{2007}-11d^{2007}\right)^{2006}}\)
f)\(\frac{\left(20a^{2007}-11c^{2007}\right)^{2006}}{\left(20a^{2006}+11c^{2006}\right)^{2007}}=\frac{\left(20b^{2007}-11d^{2007}\right)^{2006}}{\left(20b^{2006}+11d^{2006}\right)^{2007}}\)