Billy had 21 marbles. His friend gave him some more. He then had 35 marbles. Write an expression that shows how many marbles he had.
21 + x = 35
200
Twice a number decreased by 9 is 16
2n - 9 = 16
200
Which of the following shows this information correctly: Sam bought 3 sacks of potatoes. Each sack had 15 potatoes. He gave one sack to his friend Steve. How many potatoes did Sam have left?
(3 x 15) - 15 = x
300
Five less than three times a number
3n - 5
300
Maggie had 25 cookies. She gave some to her sister. She then bought 12 more at the bake sale. Which expression shows this information?
(25 - x) + 12
400
3x + 1 + 8x + 9
11x + 10
400
Tyler had 17 books. He bought 5 more. He gave 3 away. Which problem matches this expression?