The sum of two numbers is 68. Their difference is 15. Write a system of equations you could use to solve this problem.

When george started his current job, his employer told him that at the end of the first year, he would receive two vacation days. after each year worked, his number of vacation days will double up to five work weeks (25days) of payed vacation. how many vacation days will he have in 4 years

Astore sells 4 apples for $3 and 3 oranges for $4 if pete buys 12 apples and 12 oranges how much will it cost

Arace is 10 kilometers long.markers will be placed at the beginning and end of the race course and at each 500 meter mark.how many markers are needed to mark the course for the race?