cho \(\frac{a}{b}\)= \(\frac{c}{d}\)chứng minh rằng:
a) \(\frac{a}{3a+b}=\frac{c}{3c+d}\)
b)\(\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\)
c) \(\frac{a.b}{c.d}=\frac{a^2-b^2}{c^2-d^2}\)
Cho \(\frac{a}{b}\)=\(\frac{c}{d}\)chứng minh rằng
a)\(\frac{a}{a-b}\)=\(\frac{c}{c-d}\)
b)\(\frac{a}{b}=\frac{a+c}{b+d}\)
c)\(\frac{a}{3a+b}=\frac{c}{3c+d}\)
d)\(\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\)
f)\(\frac{a.b}{c.d}=\frac{\left(a-b\right)^2}{\left(c-d\right)^2}\)
1. Chứng minh tỉ lệ thức:
Cho \(\frac{a}{b}=\frac{c}{d}\) , chứng minh rằng :
a, \(\frac{a}{3a+b}\) \(=\frac{c}{3c+d}\)
b, \(\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\)
c, \(\frac{a.b}{c.d}=\frac{a^2-b^2}{c^2-d^2}\)
Có a/b=c/d chứng minh rằng \(\frac{a^2}{b^2}=\frac{c^2}{d^2}=\frac{a.c}{b.d}\)
Cho tỉ lệ thức \(\frac{a}{b}=\frac{c}{d}\).Chứng minh rằng ;
\(\frac{a.b}{c.d}=\frac{a^2-b^2}{c^2-d^2}\)và \(\left(\frac{a+b}{c+d}\right)^2=\frac{a^2+b^2}{c^2+d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\). Chứng minh: \(\frac{2.a^2-3.a.b+3.b^2}{2.b^2+3.a.b}=\frac{2.c^2-3.c.d+5.d^2}{2.d^2+3.c.d}\)
cho \(\frac{a}{b}=\frac{c}{d}\)
chứng minh rằng \(\frac{a.b}{c.d}=\frac{a^2-b^2}{c^2-d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)CMR:
\(a,\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\) \(b,\frac{a.c}{b.d}=\frac{a^2-c^2}{b^2-d^2}\)\(c,\frac{a.c}{b.d}=\frac{\left(a-b\right)^2}{\left(c-d\right)^2}\)
GIẢI GIÚP TỚ NHANH NHÉ! CẢM ƠN NHIỀU!
1/ cho \(\frac{a}{b}=\frac{c}{d}\)chứng minh rằng:
a) \(\frac{a.b}{c.d}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
b)\(\frac{a,d}{c.b}=\frac{\left(a+b\right).\left(a-b\right)}{\left(c+d\right).\left(c-d\right)}\)
2/ cho \(a.b=c^2\)chứng minh : \(\frac{a}{b}=\frac{\left(2a+3c\right)^2}{\left(2c+3b\right)^2}\)