Dat a/b=c/d=k
suy ra a=bk,b=dk ta co
+ x= 5a+3b/5a-3b=5bk+3b/5bk-3b=b(5k+3)/ b(5k-3)=5k+3/5k-3 (1)
+ y= 5c+3d/5c-3d=5dk+3d/5dk-3d=d(5k+3)/ d(5k-3)=5k+3/5k-3 (2)
tu (1) va (2) suy ra x=y
nao dung cho mink!
\(Cho\frac{a}{b}=\frac{c}{d}.Tính\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
\(cho\frac{a}{b}=\frac{c}{d}CMR\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
Chứng minh rằng: Nếu \(\frac{a}{c}=\frac{b}{d}\)thì \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
Chứng minh rằng nếu
\(\frac{a}{b}=\frac{c}{d}\)thì \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
CMR nếu a/b=c/d thì : \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
1.
a) Chứng minh rằng nếu \(\frac{a}{b}=\frac{c}{d}\) thì \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\) (giả thiết các tỉ số đều bằng nhau)
b) Tìm x biết: \(\frac{x-1}{2004}+\frac{x-2}{2003}-\frac{x-3}{2002}=\frac{x-4}{2001}\)
Cho \(\frac{a}{b}=\frac{c}{d}\) CMR \(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
chứng minh rằng \(\frac{a}{b}=\frac{c}{d}\)thì
\(\frac{5a+3b}{5a-3b}=\frac{5c+3d}{5c-3d}\)
1 a) 2a=3b:5b=7c và 3a +5c-7b=30
b)\(\frac{x-1}{2}=\frac{x+3}{4}=\frac{z-5}{6}\)và 5z-3x-4y=50
c)3x=4y=6z và x-3y+2z=70
d)\(\frac{6}{11}x=\frac{9}{2}y=\frac{18}{5}z\)và x+y+z=20
2 cho \(\frac{a}{b}=\frac{c}{d}\)và a;b;c;d\(\ne\)0
a)\(\frac{a}{a-b}\frac{c}{d}\)
b)\(\frac{ac}{bd}=\frac{a^2+c^2}{b^2+d^2}\)
c)\(\frac{a}{3a+b}=\frac{c}{3c+d}\)
d)\(\frac{a^2-b^2}{c^2-d^2}=\frac{ab}{cd}\)
g)\(\frac{5a+3b}{5c+3b}=\frac{5a-3b}{5c-3d}\)
h)\(\frac{2a+3b}{2a-3d}=\frac{2c+3d}{2c-3d}\)
