Разложите на множители (способ группировки) :

1) а²+ab+ax+bx

2) х+у-х²-ху

3) 6m-12-2n+mn

4) 4ab²+5ab+a

1) a²+ab+ax+bx=a (a+b) + x (a+b) = (a+b) (a+x)

2) x+y-x²-xy = (x+y) - x (x+y) = (x+y) (1-x)

3) 6m-12-2n+mn=6 (m-2) + n (-2+m) = 6 (m-2) + n (m-2) = (m-2) (6+n)

4) 4ab²+5ab+a=a (4b²+5b+1) = a (b+1) (4b+1)

4b²+5b+1 = *)

D=5²-4*4*1=25-16=9

b = (-5-3) / (2*4) = - 8/8=-1

b = (-5+3) / (2*4) = - 2/8=-1/4

*) = 4 (b+1) (b+1/4) = (b+1) (4b+1)