cho: \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\) ( với \(a,b,c\ne0;b\ne c\)) cmr: \(\frac{a}{c}=\frac{a-c}{c-b}\)
cho \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\left(a,b,c\ne0;b\ne c\right)\)) chứng minh rằng : \(\frac{a}{b}=\frac{a-c}{c-b}\)
Cho \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\left(a,b,c\ne0,b\ne c\right)\).Chứng minh rằng\(\frac{a}{b}=\frac{a-c}{c-b}\)
Cho \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\)(với a,b,c \(\ne0\); b\(\ne c\)) CMR : \(\frac{a}{b}=\frac{a-c}{c-b}\)
Cho: \(\frac{1}{c}=\frac{1}{2}.\left(\frac{1}{a}+\frac{1}{b},\right)\left(a,b,c\ne0,b\ne c\right)\) Chứng minh rằng: \(\frac{a}{b}=\frac{a-b}{c-b}\)
bài 1: cho tỉ lệ thức \(\frac{a}{b}=\frac{c}{d}\)
a) CMR: (a+2c)(b+d)=(a+c)(b+2d) \(\left(b,d\ne0\right)\)
b) CMR: (a+c)(b-d)=ab-cd
c) CMR: \(\frac{a}{a-b}=\frac{c}{c-d}\left(a,b,c,d>0;a\ne b,c\ne d\right)\)
bài 2: cho \(\frac{a}{b}=\frac{b}{c}=\frac{c}{d}CMR:\left(\frac{a+b+c}{b+c+d}\right)^3=\frac{a}{d}\)
cmr nếu\(a\left(z+y\right)=b\left(z+x\right)=c\left(x+y\right);a\ne b\ne c\ne0\Rightarrow\frac{y-z}{a\left(b-c\right)}=\frac{z-x}{b\left(c-a\right)}=\frac{x-y}{c\left(a-b\right)}\)
1 . Cho \(\frac{2bz-3cy}{a}=\frac{3cx-az}{2b}=\frac{ay-2bx}{3c}\)
Chứng minh \(\frac{x}{a}=\frac{y}{2b}=\frac{z}{3c}\)
2 . Cho \(\frac{1}{c}=\frac{1}{2}\left(\frac{1}{a}+\frac{1}{b}\right)\left(\forall a,b,c\ne0;b\ne c\right)\). CMR : \(\frac{a}{b}=\frac{a-c}{c-b}\)
CMR: Nếu a(y+z)=b(z+x)=c(x+y)\(\left(a\ne b\ne c\ne0\right)\)thì \(\frac{y-z}{a\left(b-c\right)}=\frac{z-x}{b\left(c-a\right)}=\frac{x-y}{c\left(a-b\right)}\)