Question

Упростите выражения: 2) -9c^2+(3c+d)^2-d^2 4) (7b-t)(t+7b)+(7b+t)^2 6) (11c+3)^2-2c(5,5c+33)

Answer 1

2)=   -9с²+9с²+d²-d²=0

4)=  (7b-t)(7b+t)+49b²+t²=49b²-t²+49b²+t²=98b²

6) =121c²+9-(11c²+66c)=121c²+9-11c²-66c=110c²+9-66c