Idon’t understand solving algebraic expressions

Two times a number plus three times another number equals 4. three times the first number plus four times the other number is 7. find the numbers

Laura read 1/8 of a comic book in 2 days. she reads the same number of pages every day. what part of the book does she read in a week

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?