1.Что это за морфема?

2.Для чего используется в языке?

3.Где обычно стоит в слове?

3ˆ√X+7  +  √X+3  = 0

(корень кубический из X+7 прибавить корень квадратный из х+3 равно 0)

75-(3x+1)=50 ПОмогите!!!!!!!!!!!

Поставить нужные времена.

1) Jane was anry because Mark wasn't calling / hadn't called her since last weekend.

2) Sophie had a headache because her baby sister had been crying / was crying all afternoon.

3) Joanna switched / had switched the TV off and went to bed.

4) Mike slipped and twisted his ankle while he was playing / had played football yesterday.

5) Tony was shocked. He couldn't believe what had just happened / just happened.

6) After John had parked / had been parking the car, he went into the house.

7) This time yesterday, we lay / were lying on the beach sunbathing.

8) I didn't go out last night because i wasn't finishing / hadn't finished my homework.

9) Jack had been working / was working at the company for ten years before he left.

10) He was driving / had been driving for an hour when the car broke down.