Cho a,b,c e R t/m a²+b²+c²=a+2b+3c=14. Tính M= abc

Giair hệ pt \(\left\{{}\begin{matrix}x^2+4y^2+3=4x\\x^3+12x+8y^3=6x^2+9\end{matrix}\right.\)

Giải hệ pt \(\left\{{}\begin{matrix}x^2+\left(y+1\right)^2=xy+x+1\\2x^3=x+y+1\end{matrix}\right.\)

Giải hệ pt \(\left\{{}\begin{matrix}x^2+\left(y+1\right)^2=xy+x+1\\2x^3=x+y+1\end{matrix}\right.\)

Cho \(\left(a+b\right)^3+4ab\ge2.\)Tìm min \(A=3\left(a^4+b^4+a^2b^2\right)-2\left(a^2+b^2\right)+1\)