Question 88892
 simplifying each expression.
1. 18y^2-12y^2
2. (-4x^2-5x+3)-(3x^2+3x-1)+(5x^2-4x+9)
3. -3(y^2+2y-4)-8(2y^2-2y+3)


  1)18y^2-12y^2 = y^2(18-12) = y^2(6) = 6y^2


  2)(-4x^2-5x+3)-(3x^2+3x-1)+(5x^2-4x+9)
    = -4x^2-5x+3-3x^2-3x+1+5x^2-4x+9
    = -4x^2-3x^2+5x^2-5x-3x-4x+3+1+9
    = x^2(-4-3+5)+x(-5-3-4)+(3+1+9)
    =x^2(-2)+x(-12)+(13)
    = -2x^2-12x+13


  3)-3(y^2+2y-4)-8(2y^2-2y+3)
    = -3y^2-6y+14-18y^2+16y-24
    = -3y^2-18y^2-6y+16y+14-24
    = -y^2(3+18)+y(-6+16)+(14-24)
    = -21y^2+10y-10