A) 8am-4ab

b) m (a-b) - (b-a)

c) 49x²-25y²

d) x²-4x-12

e) y²+9,7y-3

A) 8am-4ab=4 а (2m-b)

b) m (a-b) - (b-a) =

m (a-b) + (a-b) =

(a-b) (m+1)

c) 49x²-25y²=

(7x-5y) (7x+5y)

d) x²-4x-12=

(x-6) (x+2)

D=16+48=64

x1=4+8/2=12/2=6

x2=4-8/2=-4/2=-2

e) y²+9,7y-3=

(y-0,3) (y+10)

D = 94,09+12=106,09 (10,3²)

y1=-9,7+10,3/2=0,6/2=0,3

y2=-9,7-10,3/2=-20/2=-10