мне очень срочно надо помогите на сегодня надо.
пара чисел (-2,3)является решением системы уравнений {3x-by+4b=--1 {ax+2y+a+b=19
найдите значение a b

вставьте mustn't или needn't

1. you...wash up. i can do it.

2. you...join this queue to the cafe. i've got sandwiches and coke.

3.you...open this door. it's broken.

4.you...go out. it's very cold.

5.you...translate this text.

6.you...go shopping. we've got  a lot of food.

7.you...read this book. it's not for children.