Определите закономерность построения последовательности

- 1 1/19; 2 2/19; -3 3/19; 4 4/19;...... 
Вычислите  наиболее удобным способом сумму
первых 38 чисел последовательно 

УпроститеУпростите выражение и найдите его значение 16 х+7-(9х-15),при х=0,7

в пекарне за 3 дня израсходовали 48 мешков муки.На сколько дней хватит 80 мешков муки,если каждый день будет расходоваться одинаковое количество муки? Составь задачу,обратную данной,и реши ее.

1) Uses the correct tence-forms of the verbs in brackets.

 1. We can't go out yet. It (to rain) hard.

 2.She (to get up) early tomorrow morning.

 3.It (to be) a fine day today. There (to be) some cloud in the sky ,but  the sun (to shine).

 4.Where you (to do)?-I (to do) to the library.I usually (to get) ready for the seminars there.

 5.Susan (to lose) much  weight on her diet. She (to look) rather slim now.

 6.If the day (to be) warm next Sunday, we (to go) to the country.

 7.Could you find out what time the train (to leave)?

2) Fill in the article "a" or "the" where necessary.

1.Where are ... children?- They are in... siting-room.They are watching ...new film.

2.We usually do... lot during our English lessons. We read and translate... texts and write ... short distations.

3.Could you tell me where you put... money?

4."How did you like ... performance?" she asked.

5.London , ... capital of England,is... largest city in the world.