Cô-Si 2 số dương:
\(\hept{\begin{cases}a+b\ge2\sqrt{ab}\\b+c\ge2\sqrt{bc}\\c+a\ge2\sqrt{ca}\end{cases}}\)
\(=>\left(a+b\right)\left(b+c\right)\left(c+a\right)\ge2\sqrt{ab}.2\sqrt{bc}.2\sqrt{ca}=\left(2.2.2\right)\left(\sqrt{ab}.\sqrt{bc}.\sqrt{ca}\right)=8abc\)
Cho a,b,c>0 va a3+b3+c3=3abc
C/m a=b=c
cho a+b+c=0 va a³+b³+c³=0. Tinh A= a^2017+b^2017+c^2017.
cho a+b+c=0 . CMR H=K biet H=a(a+b)(a+c) va K=c(c+a)(c+b)
cho a,b,c la 3 so khac 0 va a+b+c=0 chung minh rang 1/a^2+b^2-c^2+1/b^2+c^2-a^2+1/c^2+a^2-b^2=0
cho cc số a;b; thỏa mãn a+b+c khac 0 va\(\frac{a+b}{c}=\frac{b+c}{a}=\frac{c+a}{b}\) khi đó giá trị của M=\(\left(1+\frac{a}{b}\right)\left(1+\frac{b}{c}\right)\left(1+\frac{c}{a}\right)=\)?
cho a+b+c=1 va 1/a+1/b+1/c=0.Chung minh rang : a^2+b^2+c^2=0
Cho a,b,c,d la cac so khac 0 va
( a + b + c + d ) . ( a - b - c + d ) = ( a - b + c - d ) . ( a + b - c - d )
CMR : a/c = b/d
cho a+b+c=0 va a binh phuong+ b binh phuong+ c binh phuing=1 .tinh m=a mu 4 + b mu 4 + c mu 4
cho a,b,c >0 va 1/a+1/c=2/b
Tim GTNN A=(a+b)/(2a-b) + (b+c)/(2c-b)
