RÚT GỌN
\(a.-3x\left(x+2\right)^2+\left(x+3\right)\left(x-1\right)\left(x+1\right)-\left(2x-3\right)^2\) \(\left(x-3\right)\left(x+3\right)\left(x+2\right)-\left(x-1\right)-\left(x^2-3\right)-5x\left(x+4\right)^2-\left(x-5\right)^2\)
\(c.2x\left(x-4\right)^2-\left(x+5\right)\left(x-2\right)\left(x+2\right)+2\left(x+5\right)^2-\left(x-1\right)^2\) \(d.-3x\left(x+2\right)^2+\left(x+3\right)\left(x-1\right)\left(x+1\right)-\left(2x-3\right)^2\)
a, \(-3x\left(x^2+4x+4\right)+\left(x+3\right)\left(x^2+2x-3\right)-4x^2+12x-9\)
\(=-3x^3-12x^2-12x+x^3+2x^2-3x+3x^2+6x-9-4x^2+12x-9=-2x^3-11x^2+3x-18\)
b, \(\left(x^2-9\right)\left(x+2\right)-x+1-x^2+3-5x\left(x^2+8x+16\right)-\left(x^2-10x+25\right)\)
c, \(=x^3+2x^2-9x-18-x-x^2+4-5x^3-40x^2-80x-x^2+10x-25=-4x^3-40x^2-120x-43\)
