Đặt \(\frac{a}{b}=\frac{c}{d}=k\)
Suy ra \(\hept{\begin{cases}a=bk\\c=dk\end{cases}}\)
Xét VT \(\frac{ac}{bd}=\frac{bkdk}{bd}=\frac{bdk^2}{bd}=k^2\left(1\right)\)
Xét VP \(\frac{a^2+c^2}{b^2+d^2}=\frac{\left(bk\right)^2+\left(dk\right)^2}{b^2+d^2}=\frac{b^2k^2+d^2k^2}{b^2+d^2}=\frac{k^2\left(b^2+d^2\right)}{b^2+d^2}=k^2\left(2\right)\)
Từ (1) và (2) ->Đpcm
Cho \(\frac{a}{b}=\frac{c}{d}CMR:\frac{a^2+ac}{c^2-ac}=\frac{b^2+bd}{d^2-bd}\)
Cho \(\frac{a}{b}=\frac{c}{d}CMR:\frac{a^2+ac}{c^2-ac}=\frac{b^2+bd}{d^2-bd}\)
Cho \(\frac{a}{b}=\frac{c}{d}CMR:\frac{a^2+ac}{c^2-ac}=\frac{b^2+bd}{d^2-bd}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)
CMR:\(\frac{a^2+ac}{c^2-ac}=\frac{b^2+bd}{d^2-bd}\)
Cho \(\frac{a}{b}=\frac{c}{d}\). CMR \(\frac{a^2+ac}{c^2-ac}=\frac{a^2-bd}{c^2+bd}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)
CMR \(\frac{a^2+ac}{c^2-ac}=\frac{b^2+bd}{d^2-bd}\)
#Giúp hộ nha♥
Cho tỉ lệ thức \(\frac{a}{b}=\frac{c}{d}\)
CMR \(\frac{ac}{bd}=\frac{a^2+c^2}{b^2+d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\).CMR :
a/ \(\frac{a+c}{b+d}=\frac{a-c}{b-d}\)
b/\(\frac{2a+3c}{2d+3d}=\frac{2a-3c}{2b-3d}\)
c/\(\frac{a^2+c^2}{b^2+d^2}=\frac{ac^2}{bd}\)
Cho tỷ lệ thức \(\frac{a}{b}=\frac{c}{d}\) ( b,d khác 0 )
CMR : \(\frac{ac}{bd}=\frac{a^2+c^2}{b^2+d^2}\)
