[tex]1. \\\\a) \\(2x+3)(y-3)=2x*y+2x*(-3)+3*y+3*(-3)=2xy-6x+3y-6\\\\b) \\(a-4)(a^2-2b^2)=a*a^2+a*(-2b^2)-4*a^2-4*(-2b^2)=a^3-2ab^2-4a^2+8b^2[/tex]
[tex]2. \\\\a) \\-(3c+1)(c-1)-c(c-3)=-(3c^2-3c+c-1)-c^2+3c=-3c^2+2c+1-c^2+3c=-4c^2+5c+1\\\\b) \\5x^2(x^2+2)-(x^2-1)(x^2+3)=5x^4+10x^2-(x^4+3x^2-x^2-3)=5x^4+10x^2-x^4-2x^2+3=4x^4+8x^2+3[/tex]
