[tex]a) \ (3x+7)x-(7+3x)x^{2} = (3x+7)(x-x^{2}) = x(3x+7)(1-x)\\\\b) \ y^{3}(4y+3)+(3+4y)y = y(4y+3)(y^{2}+1)\\\\c) \ (a-b)z + 5(b-a) = (a-b)z - 5(a-b) = (a-b)(z-5)\\\\d) \ 3x(2a-5b) -x^{2}(5c-2a) = 3x(2a-5b) + x^{2}(2a-5b) = x(2a-5b)(3+x)[/tex]
[tex]e) \ (2x-1)y + (1-2x)-z(1-2x) = (1-2x)(-y+1-z)=(2x-1)(y-1+z) \\\\f) \ x^{2}(4-x)-x(x-4)+(4-x)=(4-x)(x^{2}+x+1)\\\\g) \ 3(7x-3)x^{2}+6x(3-7x) = 3x(7x-3)(x-2)\\\\h) \ (2y-6)y -2(y-3)y^{2} = 2y(y-3)-2y^{2}(y-3) = 2y(y-3)(1-y)[/tex]
