Tuyển Cộng tác viên Hoc24 nhiệm kì 26 tại đây: https://forms.gle/dK3zGK3LHFrgvTkJ6
Ta có : \(\frac{a}{b}=\frac{c}{d}\)
Áp dụng tính chất dãy tỉ số bằng nhau ta có:
\(\frac{a}{c}=\frac{b}{d}=\frac{5a}{5c}=\frac{3b}{3d}=\frac{5a+3b}{5c+3d}=\frac{5a-3b}{5c-3d}\)
=> \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
a) Cho \(\dfrac{a}{b}\)=\(\dfrac{c}{d}\) CMR: \(\dfrac{5a+3b}{5a-3b}\)=\(\dfrac{5c+3d}{5c-3d}\)
b) CMR: Nếu \(\dfrac{a}{b}\)=\(\dfrac{c}{d}\) thì : \(\dfrac{a}{b}\)=\(\dfrac{3a+2c}{3b+2d}\)
c) CMR: Nếu \(\dfrac{a}{b}\)=\(\dfrac{c}{d}\) thì \(\dfrac{7a^2+3ab}{11a^2-8b^2}\) = \(\dfrac{7c^2+3cd}{11c^{2^{ }}-8d^2}\)
CMR nếu a/b=c/d thì 5a+3b/5a-3b = 5c+3d/5c-3d ( bằng 3 cách )
CMR nếu a/b=c/d thì : \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
cho a/b=c/d. CMR:5a+3b/5c=3d=3d=5a-3b/5c-3d
bài 4 cmr nếu a/b=c/d thì
a. 5a+3b/5a-3b=5c+3d/5c-3d
b.7a^2+3ab/11a^2-8b^2/7c^2+3cd/11c^2-8b^2
cho a/b =c/d ( a,b,c,dkhác 0)
CMR :
a) a-b/a+b=c-d/c+d
b) 5a+3b/5a-3b=5c+3d/5c-3d
c/m: nếu a/b=c/d thì:
a, 5a+3b/5a-3b = 5c+3d/5c-3d
\(cho\frac{a}{b}=\frac{c}{d}CMR\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
CM nếu a/b=c/d thì (5a+3b)/ (5a-3b)= (5c+3d)/(5c-3d)
