factoriser:
A=(x+1)(x-4)+3x+3
B=[9(x*x)-25]+(6x+10)
A=(x+1)(x-4)+3(x+1)
A=(x+1)(x-4+3)
A=(x+1)(x-1)
B=[(3x)²-5²]+( 2*3x + 2*5)
B=(3x-5)(3x+5)+2(3x+5)
B=(3x+5)(3x-5+2)
B=(3x+5)(3x-3)
B=3(3x+5)(x-1)
