Question

giúp mik vs ạ mik cần gấp

Answer 1

Bài 8 

a, \(A=a^2+b^2=\left(a+b\right)^2-2ab\Rightarrow S^2-2P\)

b, \(B=a^3+b^3=\left(a+b\right)\left(a^2-ab+b^2\right)=\left(a+b\right)\left[\left(a+b\right)^2-3ab\right]\)

\(\Rightarrow S\left(S^2-3P\right)=S^3-3PS\)

c, \(C=a^4+b^4=\left(a^2+b^2\right)^2-2a^2b^2=\left[\left(a+b\right)^2-2ab\right]^2-2\left(ab\right)^2\)

\(\Rightarrow\left(S^2-2P\right)^2-2P^2\)