How and why does this equation -8-x=-3x equal x=4

Plz me plz i will give a brain just plz

30 points! here is a you are the new manager at trusty goods wholesale produce. you need to figure out how to adjust the amount of produce in your notes after the events of the day: you got 5 more crates of bananas someone returned 2 crates of apples a worker dropped a crate of grapes (oh no! , you had to throw them out) you sold a crate of bananas you sold 5 crates of apples can you write an expression to describe your day using: "a" for crates of apples "b" for crates of bananas and "g" for crates of grapes? make sure the expression is in simplest form question 2 (3 points) explain your steps using sentences.

1. according to the internal revenue service, the mean tax refund for the year 2007 was $2,708. assume the standard deviation is $650 and that the amounts refunded follow a normal probability distribution. a. what percent of the refunds are more than $3,000? b. what percent of the refunds are more than $3,000 but less than $4,000? c. what percent of the refunds are less than $2,000?