Chứng minh rằng: nếu a b = c d thì
a ) 5 a + 3 b 5 a − 3 b = 5 c + 3 d 5 c − 3 d
b ) 7 a 2 + 3 a b 11 a 2 − 8 b 2 = 7 c 2 + 3 c d 11 c 2 − 8 d 2
\(Cho\)\(\dfrac{a}{b}\)
\(Chứng\) \(Minh\)
\(\dfrac{7a^2+3ab}{11a^2-8b}\)\(=\)\(\dfrac{7c^2+3cd}{11c^2-8d}\)
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
\(\dfrac{7a^2+3ab}{11a^2+8b^2}=\dfrac{7c^2+3cd}{11c^2-8d^2}\)
Cho a/b = c/d với a, b, c, d > 0. Chứng minh rằng\(\dfrac{7a^2+3ab}{11a^2-8b^2}=\dfrac{7c^2+3cd}{11c^2-8d^2}\)
cho a/b= c/d thì
chứng minh\(\frac{7a^2-3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8d^2}\)
Cho tỉ lệ thức\(\dfrac{a}{b}\)=\(\dfrac{c}{d}\). Chứng minh rằng ta có tỉ lệ sau: \(\dfrac{7a^2+3ab}{11a^2-8b^2}\)=\(\dfrac{7c^2+3cd}{11c^2-8d^2}\)
Cho a/b=c/d . Hãy chứng minh \(\frac{7a^2+3ab}{11a^2-8b^2}=\frac{7c^2+3cd}{11c^2-8b^2}\)
cho a/b = c/d chứng minh rằng 7a2+3ab /11a2- 8b2=7c2+3cd / 11c2-8d2