bonjour
ex 57
x 5x -1
-2x -10x² +2x
-3 -15x +3
2)(5x-1)(-2x-3)
=-10x²-15x+2x+3
=-10x²-13x+3
ex 58
a)(x-2)(3x+1)
3x²+x-6x-2
3x²-5x-2
b)(6-3x)(7x-5)
42x-30-21x²+15x
-21x²+57x-30
c)(-x+3)(x-3)
-x²+3x+3x-9
-x²+6x-9
d)(-2-3x)(-4-5x)
8+10x+12x+15x²
15x²+22x+8
