Ta có : \(\frac{a}{b}=\frac{c}{d}=\frac{a}{c}=\frac{b}{d}=\frac{a+b}{c+d}\)
\(\Rightarrow\frac{a}{c}.\frac{b}{d}=\frac{a+b}{c+d}.\frac{a+b}{c+d}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
\(\Rightarrow\frac{ab}{cd}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}.CMR:\frac{ab}{cd}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\). CMR:
a) \(\frac{a^2-b^2}{c^2-d^2}=\frac{ab}{cd}\)
b) \(\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{ab}{cd}\)
Cho \(\frac{a}{b}=\frac{c}{d}\), CMR:
a) \(\frac{a^2-b^2}{c^2-d^2}=\frac{ab}{cd}\)
b)\(\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{ab}{cd}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)CMR:
a,\(\frac{2a^2-3b^2}{2c^2-3d^2}=\frac{ab}{cd}\)
b,\(\frac{ab}{cd}=\frac{\left(a-2b\right)^2}{\left(c-2d\right)^2}\)
1, Cho \(\frac{a}{b}=\frac{c}{d}\)( b,c,d khác 0; c+đ khác 0). CMR:
\(\frac{ab}{cd}=\frac{\left(a+b\right)^2}{\left(c+\text{d}\right)^2}\)
cho tỉ lệ thức sau \(\frac{a}{b}=\frac{c}{d}\):
CMR:
a\(\frac{a^2-b^2}{ab}=\frac{c^2-d^2}{cd}\)
b\(\frac{\left(a+b\right)^2}{a^2+b^2}=\frac{\left(c+d\right)^2}{c^2+d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)
CMR: \(\frac{ab}{cd}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
Cho\(\frac{a}{b}=\frac{c}{d}\).CMR:
a,\(\frac{a^2-b^2}{c^2-d^2}=\frac{ab}{cd}\) b,\(\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{ab}{cd}\)
Cho \(\frac{a}{b}\)=\(\frac{c}{d}\) CMr \(\frac{ab}{cd}\) \(\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
