Question 88893
  Find each product
1.(3x)(4x^3)(-x^5)
2.5x^3(4x^5-2x)
3. (5x-2y)^2
4. (5x+1)(3x^2-3x-2)


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



   2)5x^3(4x^5-2x)
    = (5x^3)(4x^5)- (5x^3)(2x)
    = (20x^3+5)-(10x^3+1)
    = 20x^8-10x^4



   3)(5x-2y)^2
     = (5x)^2-2*5x*2y+(2y)^2
     = 25x^2-20xy=4y^2




   4)(5x+1)(3x^2-3x-2)
     = 5x(3x^2-3x-2)+1(3x^2-3x-2)
     = 15x^3-15x^2-10x+3x^2-3x-2
     = 15x^3-12x^2-13x-2