cho \(\frac{a}{2003}=\frac{b}{2004}=\frac{c}{2005}\)CMR 4(a-b)(b-c)=\(\left(c-a\right)^2\)
cho \(\frac{a}{b}=\frac{c}{d}\) chứng minh rằng :\(\frac{ab}{cd}=\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
cho \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\)vơi a,b,c \(\ne\) 0; b\(\ne\) c chứng minh rằng \(\frac{a}{b}=\frac{a-c}{c-b}\)
Cho \(\frac{a}{c}\)=\(\frac{c}{b}\) Chứng minh rằng b2 - a2 / a2 + c2 = \(\frac{b-c}{a}\)
Cho tỉ lệ thức \(\frac{a}{b}=\frac{c}{d}\)
Chứng minh rằng
a)\(\frac{a.b}{c.d}=\frac{a^2-b^2}{c^2-d^2}\)
b)\(\left(\frac{a+b}{c+d}\right)^2=\frac{a^2+b^2}{c^2+d^2}\)
cho \(\frac{a}{b}=\frac{c}{d}\) chứng minh rằng: \(\frac{ac}{bd}=\frac{a^2+c^2}{b^2+d^2}\)
cho \(\frac{a}{b}=\frac{c}{d}\)chứng minh rằng:
(a+b+c+d).(a-b-c+d)=(a-b+c-d).(a+b-c-d)
cho tỉ lệ thúc \(\frac{a}{b}=\frac{c}{d}\). Chứng minh rằng
\(a,\frac{a}{3a+b}=\frac{c}{3c+d}\)
\(b,\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{ab}{cd}\)
Cho \(\frac{a}{c}\)= \(\frac{c}{b}\). Chứng minh rằng \(\frac{a^2+c^2}{b^2+c^2}\)= \(\frac{a}{b}\)
