Одна швея может выполнить работу за 4ч, другая- за 5ч. какую часть работы выполнят они, работая вместе; за 2ч, за 1/2ч, за 3/4ч?

3-mx=2m(x+1)-1

x-?

Правильно написанно(граматика) И укажите где исправить

Hi!I received your letter! I was glad of hearing from you as well! Thanks for your invitation. But I am compelled to upset you, I can't go with you on concert. The matter is that my parents are going to go  to the cinema and I will be compelled to nurse my little brother. On the next week i wiil be free and we can go on another concert. Thanks for understanding! Well will have fine.