\(4.\left(2x+3\right)\left(2x-1\right)\left(x-3\right)\left(4x+1\right)+44x^2\)
\(=4.\left(4x^2+4x-3\right)\left(4x^2-11x-3\right)+44x^2\)
Đặt \(4x^2+4x-3=t\)
\(\Rightarrow4.\left(2x+3\right)\left(2x-1\right)\left(x-3\right)\left(4x+1\right)+44x^2\)
\(=4.t.\left(t-15x\right)+44x^2\)
\(=4t^2-60tx+44x^2\)
\(=4.\left(t^2-15tx+11x^2\right)\)
Tự lm nốt nhé~