A box of cereal states that there are calories in a -cup serving. What is the unit rate for calories per cup? How many calories are there in of the cereal?

What does x = in this equation x+3+2x=x+5

Having a hard time understanding this question (see attachment).

The numbers on a football field indicate 10 yard increments. you walk around the perimeter of a football field between the pylons. you walk a distance of 30623 yards. find the area and perimeter of the indicated regions. write your answers as mixed numbers, if necessary. a. one end zone: perimeter: yd area: yd2 b. the playing field (not including end zones): perimeter: yd area: yd2 c. the playing field (including end zones): perimeter: yd area: yd2