(5-t)+(5-t)(t+2)+(5-t)(t-11)=? памагите

(5-t)+(5-t)(t+2)+(5-t)(t-11)=(5-t)(1+t+2+t-11)=(5-t)(2t-8)=10t-40-2t^2+8t=18t-2t^2-40