Lời giải:
Đặt $\frac{a}{b}=\frac{c}{d}=k\Rightarrow a=bk; c=dk$. Khi đó:
$\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7(bk)^2+3bk.b}{11(bk)^2-8b^2}$
$=\frac{b^2(7k^2+3k)}{b^2(11k^2-8)}=\frac{7k^2+3k}{11k^2-8}(1)$
Và:
$\frac{7c^2+3cd}{11c^2-8d^2}=\frac{7(dk)^2+3dk.d}{11(dk)^2-8d^2}$
$=\frac{d^2(7k^2+3k)}{d^2(11k^2-8)}=\frac{7k^2+3k}{11k^2-8}(2)$
Từ $(1); (2)$ ta có đpcm.
CMR nếu a/b=c/d thì\(\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8d^2}\)
cho a/b = c/d . cmr 7a mũ 2 + 3cd / 11a mũ 2 - 8b mũ 2 = 7c mũ 2 + 3cd / 11c mũ 2 - 8d mũ 2
cho a/b = c/d . cmr 7a mũ 2 + 3cd / 11a mũ 2 - 8b mũ 2 = 7c mũ 2 + 3cd / 11c mũ 2 - 8d mũ 2
CMR nếu a/c =b/d thì:
\(\frac{7a^2+3ab}{11a^2+8b^2}=\frac{7c^2+3cd}{11c^2+8d^2}\)
CMR:nếu a/b=c/d thì a)5a+3b/5a-3b ; b)7a^2+3ab/11a^2-8b^2=7c^2+3cd/11c^2-8d^2
C/m : nếu a/b = c/d thì
\(\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8d^2}\)
Cho \(\frac{a}{b}=\frac{c}{d}.CMR:\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8d^2}\)
Hẹp me
Cho \(\dfrac{a}{b}=\dfrac{c}{d}\) Chứng minh:
\(\dfrac{7a^2+3ab}{11a^2-8b^2}=\dfrac{7c^2+3cd}{11c^2-8d^2}\)
cho \(\dfrac{a}{b}=\dfrac{c}{d}\) Chứng minh rằng
\(\dfrac{7a^2+3ab}{11a^2+8b^2}=\dfrac{7c^2+3cd}{11c^2-8d^2}\)
