Cho tỉ lệ thức \(\frac{a}{b}=\frac{c}{d}\)C/m:
a)\(\frac{a+b}{b}=\frac{c+d}{d}\)
b)\(\frac{â-b}{b}=\frac{c-d}{d}\)
c)\(\frac{a+b}{a}=\frac{c+d}{c}\)
d)\(\frac{a-b}{a}=\frac{c-d}{c}\)
e)\(\frac{a}{a+b}=\frac{c}{c+d}\)
f)\(\frac{a}{a-b}=\frac{c}{c-d}\)
g)\(\frac{a^2+b^2}{c^2+d^2}=\frac{\left(a+b\right)^2}{\left(c+d\right)^2}\)
h)\(\frac{\left(a-b\right)^2}{\left(c-d\right)^2}=\frac{a^4+b^4}{c^4+d^4}\)
( áp dụng t/c tỉ lệ thức và dãy tỉ số = nhau)
a,a/b=c/d
<=>a/b+1=c/d+1
<=>a/b+b/b=c/d+d/d
=>a+b/b=c+d/d
b,a/b=c/d
<=>a/b-1=c/d-1
<=>a/b-b/b=c/d-d/d
<=>a-b/b=c-d/d
a,a/b=c/d
=>ad=bc
=>ad+bd=bc+bd
=>d(a+b)=b(c+d)
=>a+b/b=c+d/d
ko bt đ ko
