a: \(=4x^2+4xy+y^2+x^2y^2+2\left(2x^2-2xy+xy-y^2\right)\)
\(=4x^2+4xy+y^2+x^2y^2+4x^2-2xy-2y^2\)
\(=8x^2+2xy+x^2y^2-y^2\)
b: \(5\left(2x-1\right)^2+4\left(x-1\right)\left(x+3\right)-2\left(5-3x\right)^2\)
\(=5\left(4x^2-4x+1\right)+4\left(x^2+3x-x-3\right)-2\left(9x^2-30x+25\right)\)
\(=20x^2-20x+5+4x^2+8x-12-18x^2+60x-50\)
\(=6x^2+48x-57\)