cho cac so a,b,c va thoa man \(\frac{ab}{a+b}=\frac{1}{3},\frac{bc}{b+c}=\frac{1}{4},\frac{ca}{c+a}=\frac{1}{5}\)Tinh gia tri bieu thuc P=\(\frac{1}{a}+\frac{1}{b}+\frac{1}{c}\)
Cho cac so a,b,c,d thoa man: \(\frac{a}{b+c+d}=\frac{b}{c+d+a}=\frac{c}{d+a+b}=\)
\(\frac{d}{a+b+c}\). Tinh gia tri bieu thuc:
P=\(\frac{a+b}{c+d}=\frac{b+c}{d+a}=\frac{c+d}{b+a}=\frac{d+a}{b+c}\)
Gia su a,b,c la cacso thoa man a+b+c=259 va \(\frac{1}{a+b}+\frac{1}{b+c}+\frac{1}{a+c}=15\). Khi do gia tri cua bieu thuc \(Q=\frac{a}{b+c}+\frac{b}{a+c}+\frac{c}{a+b}\)bang
Cho a,b,c là cac so thoa man dieu kien \(\frac{2a-b}{a+b}=\frac{b-c+a}{2a-b}=\frac{2}{3}\)
Khi đo gia tri cua bieu thuc \(P=\frac{\left(5b+4a\right)^5}{\left(5b+4c\right)^2.\left(a+3c\right)^3}\)
a, cho day ti so bang nhau : \(\frac{2a+b+c+d}{a}=\frac{a+2b+c+d}{b}=\frac{a+b+2c+d}{c}=\frac{a+b+c+2d}{d}\)
tinh gia tri bieu thuc M: \(\frac{a+b}{c+d}+\frac{b+c}{d+a}+\frac{c+d}{a+b}+\frac{d+a}{b+c}\)
b,cho x= \(1+\frac{1}{2013}+\frac{1}{2013^2}+\frac{1}{2013^3}+....+\frac{1}{2013^{2013}}\)
tinh gia tri bieu thuc: S= (2012x+\(\frac{1}{2013^{2013}}\)) : 2013^2014
Cho a,b,c khac 0 thoa man: \(\frac{2a+b+c}{a}\)=\(\frac{2b+c+a}{b}\)=\(\frac{2c+a+b}{c}\)
Tinh gia tri cua bieu thuc: P=\(\frac{\left(a+b\right)\left(b+c\right)\left(c+a\right)}{abc}\)
GIUP MINH VOI NHA!
cho day ti so bang nhau
\(\frac{2a+b+c+d}{a}=\frac{a+2b+c+d}{b}=\frac{a+b+2c+d}{c}=\frac{a+b+c+2d}{d}\)
tinh gia tri bieu thuc m=\(\frac{a+b}{c+d}=\frac{b+c}{d+a}=\frac{c+d}{a+b}=\frac{d+a}{b+c}\)
\(\frac{a+b}{c}=\frac{b+c}{a}=\frac{c+a}{b}\)
tinh gia tri bieu thuc p=[1+a*b]*[1+b*c]*[1+c*a]
Biet \(\frac{-a+b+c+d}{a}=\frac{a-b+c+d}{b}=\frac{a+b-c-d}{c}=\frac{a+b+c-d}{d}\)
Tinh gia tri bieu thuc \(\left(\frac{a}{b}+1\right).\left(\frac{b}{c}+1\right).\left(\frac{c}{d}+1\right).\left(1+\frac{d}{a}\right)\)