\(\left(-A-B\right)^2=A^2+2AB+B^2\)
\(\left(-A-B\right)^2=A^2+2AB+B^2\)
a, a( b + c)2(b - c) + b( c + a)2( c - a) + c( a + b)2( a - b)
b, a( b - c )3 + b( c - a)3 + c( a - b)3
c, a2b2( a - b) + b2c2( b - c) + c2a2( c - a)
d, a( b2 + c2) + b( c2 + a2) + c( a2 + b2) - 2abc - a3 - b3 - c3
e, a4( b - c) + b4( c - a) + c4( a - b)
Cho A = \(\dfrac{b^2}{a+b}+\dfrac{c^2}{b+c}+\dfrac{a^2}{a+c}\); B= \(\dfrac{a^2}{a+b}+\dfrac{b^2}{b+c}+\dfrac{c^2}{a+c}\). CMR A = B
Cho a khác +-b và a(a+b)(a+c)=b(b+c)(b+a). Cm a+b+c=0
Cho a + b = 7, a.b = 10. Tính:
a, A = \(a^2+b^2\).
b, B = \(a^3+b^3\).
c, C = \(a^4+b^4\).
d, D = \(a^5+b^5\).
e, E = a - b.
a^2/b+c +b^2/c+a + c^2/b+a =0
Chứng minh rằng a/b+c +b/c+a +c/a+b=1
Cho \(a+b=5,ab=-2\left(a< b\right)\). Hãy tính \(a^2+b^2,\dfrac{1}{a^3}+\dfrac{1}{b^3},a-b,a^3-b^3\)
Cho \(\dfrac{a-c}{b+c}+\dfrac{b-c}{c+a}+\dfrac{c-b}{a+b}=1\) Cmr: \(\dfrac{a+b}{b+c}+\dfrac{b+c}{c+a}+\dfrac{c+a}{a+b}=4\)
Cho 2 số thực a,b khác 0 thỏa mãn (a+b)ab = a^2 +b^2 -ab. Chứng minh:
a) 4(a+b)ab = 3(a-b)^2 + (a+b)^2
b) 1/a^3 + 1/b^3 < hoặc=16
Cho a,b,c >0 .CMR:
\(\dfrac{a}{a+b}+\dfrac{b}{b+c}+\dfrac{c}{c+a}< \sqrt{\dfrac{b}{c+a}}+\sqrt{\dfrac{a}{c+b}}+\sqrt{\dfrac{c}{a+b}}\)
Cho a,b,c >0 .CMR:
\(\dfrac{a}{a+b}+\dfrac{b}{b+c}+\dfrac{c}{c+a}< \sqrt{\dfrac{a}{b+c}}+\sqrt{\dfrac{b}{c+a}}+\sqrt{\dfrac{c}{a+b}}\)