ta có: .\(\frac{a.c}{b.d}\)= \(\frac{^{a^2}}{b^2}\); \(\frac{a.c}{b.d}\)=\(\frac{c^2}{d^2}\)vậy \(\frac{a.c.b^2}{b.d}\)= a2 (1) và \(\frac{a.c.d^2}{b.d}\)= c2 (2)
(1)+(2) suy ra \(\frac{a.c}{b.d}\)= \(\frac{a^2+c^2}{b^2+d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)CMR:
\(a,\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\) \(b,\frac{a.c}{b.d}=\frac{a^2-c^2}{b^2-d^2}\)\(c,\frac{a.c}{b.d}=\frac{\left(a-b\right)^2}{\left(c-d\right)^2}\)
GIẢI GIÚP TỚ NHANH NHÉ! CẢM ƠN NHIỀU!
cho \(\frac{a}{b}=\frac{c}{d}.CMR\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\)
cho \(\frac{a}{b}=\frac{c}{d},\)(b+d khác 0), CMR\(\frac{a^2+c^2}{b^2+d^2}=\frac{a.c}{b.d}\)
Có a/b=c/d chứng minh rằng \(\frac{a^2}{b^2}=\frac{c^2}{d^2}=\frac{a.c}{b.d}\)
CHO \(a,b,c,d\ne0\)VÀ\(b^2=a.c;c^2=b.d;b^3+c^3+d^3\ne0\)
\(CMR:\frac{a^3+b^3+c^3}{b^3+c^3+d^3}=\frac{a}{d}\)
Cho \(\frac{a}{b}=\frac{c}{d}\)với a,b,c,d khác 0
C/m \(\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+d^2}\)
cho b^2 = a.c và c^2=b.d . tính \(\frac{a}{d}+\left(\frac{-a-b-c}{b+c+d}\right)^3\)
Cho \(\frac{a}{b}=\frac{c}{d}\) chứng minh :
\(\frac{a.c}{b.d}=\frac{a^2+c^2}{b^2+c^2}\)
cho \(\frac{a}{b}\)=\(\frac{c}{d}\)(b khác 0,d khác 0) chứng tỏ rằng \(\frac{a^2+c^2}{b^2+d^2}\)= \(\frac{a.c}{b.d}\)
