(-с-3)*(с+1)
(11а-4)*(3-2а)
(x-t)*(x 2 степень+2 xt-3t 2 cтепень)
1) = -c^2-c-3c-3= -c^2-4c-3
2) = 33a-22a^2-12+8a= 41a-22a^2-12
3) = x^3+2x^2t-3xt^2-x^2t-2xt^2+3t^3= x^3+x^2t-5xt^2+3t^3