Найдите значение выражения: 3а+5b-4a-2b при a=5, 3 и b= выясните, при каких значениях переменной выражение не имеет смысла

am andrew kiporuk. i am a puple of the 10th form. i get ut ap 7 o'clock. i wash myself and dress.i make a bed. my friend come to me at half past 7 and we go to the school. at school i have 7 lessons. i come back home at 3 o'clock. i have dinner. then i walk with my dog. then help my mother at home. sometime go for shopping, pour the flowers. i begin to do my homework at 5 o'clock. i watch tv very seldom, because i have many home task. sometime andrey saynov comes to me. we talk about our school business. he studied in colledge. i listen to the music very often. i have supper at 7 o'clock. after 8 o'clock my brothers come to me. and we play on the computer. at 10 o'clock i go to bed.

my name is karoyan. i’m 15 years old. i live in moskow. it’s one of the biggest and most beautiful cities in russia. i’m in my last year of school and i’m thinking of entering the polytechnic university. my parents are always helping me in every possible way with studies and pocket money, but i understand that it’s not easy to earn money. so, this year i’ve decided to find a part-time job to be able to pay for my future studies. i was lucky and i found a job at local mcdonalds. it’s a suitable job for me, as i can choose the days and hours when i can work. i chose to work at the second part of the day, as i need to go to school every morning from 8 am till 2 pm. afterwards i’m free to do what i want. so i go to work which is from 3 pm till 9. i know it’s long hours and i come back home really exhausted but the pay is good. besides, i don’t work every day. i work only on tuesdays, thursdays and saturdays. i sometimes find it difficult to keep up with my homework but i’m doing fine. i always listen attentively the new topics at the lessons and it helps me to be prepared for the following lessons. my work at mcdonalds isn’t easy, but it teaches me how to cooperate with colleagues, how to deal with customers and else. i’m sure it will help me in my future life. moreover, i always have my own pocket money and i even can buy something for our house. my parents are very proud of me.