a: \(-5x^2+3x\left(x+2\right)\)
\(=-5x^2+3x^2+6x\)
\(=-2x^2+6x\)
b: \(4x\left(x-1\right)-4x^2\)
\(=4x^2-4x-4x^2\)
=-4x
c: \(2x^2\left(-x^2-3x\right)+6x^3\)
\(=-2x^4-6x^3+6x^3\)
\(=-2x^4\)
d: \(2x^2\left(x-1\right)-5\left(x+2\right)-2x\left(x-2\right)\)
\(=2x^3-2x^2-5x-10-2x^2+4x\)
\(=2x^3-4x^2-x-10\)