1. a) x^2+5x-8x+40=x^2-3x+40
b) 12b^2-6b-8b+4=12b^2-14b+4
v) 12a^2-18ax+2ax-3x^2=
=12a^2-16ax-3x^2
г) c^3+3c^2+2c+c^2+3c+2=
=c^3+4c^2+5c+2
2. a) (x-1)(2x-3)
b) a(b+c)+4(b+c)=(b+c)(a+4)
3. -0.4a(10a^2-6a^4+15-9a^2)=
=-0.4a(a^2-6a^4+15)=2.4a^4-0.4a^3-6a
4. a) a(a+b)-3(a+b)=(a+b)(a-3)
b) p(k-x-1)-c(k-x-1)=(k-x-1)(p-c)