a) c+d+3x(c+d)=(с+d)(1+3x)
б) 2a+ax+2bx+4b=a(2+x)+2b(x+2)=(x+2)(a+2b)
в) mn-3m+3-n=m(n-3)-(n-3)=(n-3)(m-1)
г)2cx-3xy+6by-4bc=2c(x-b)-3y(x-b)=(x-b)(2c-3y)
д)x^2-3ax+6a-2x=x(x-3a)-2(x-3a)=(x-3a)(a-2)
е)a^2b-a-ab^2+b-2ab+2=a(ab-1)-b(ab-1)+2(ab+1)=(ab+1)(a-b+2)
ё)9,5*1,7-0,4*9,5+0,5*1,7-0,5*0,4=1.7(9.5+0.5)-0.4(9.5+0.5)=(9.5+0.5)(1.7-0.4)=10*1.3=13