одна машинистка может выполнить работу за 10 часов а другая за 15 часов. за сколько часов могут выполнить работу обе машинистки при совместной работе?

помогите срочно надо!! Rewrite the second sentence to mean the same as the first. use two to five words, including the word in bold
1. she's afraid of lifts, so she won't come in.
WERE If she...................................., she would come in.

2. He's ill all the time because he has a very poor diet.
HAVE If he ........................................ such poor diet, he wouldn't be ill all the time

3. I am so sad we missed Doug's art exhibition.
HAD I wish we ................................................ Doug's art exhibition.

4. If you don't leave now, we won't make it to her birthday party in time
UNLESS We won't make it to her birthdayparty in time ............................................... now.

5. He didn't stop at the traffic light and he had an accident.
STOPPED If he ............................................. traffic light, he wouldn't have had an accident.

это спотлайт, только я не знаю какой класс, если бы вы подсказали, я бы гдз нашла, спасибо заранее:)) 

Решить уравнение:

корень из( 3x+1) - корень из (x+8)=1