Show how to make a ten to solve 13-7

Jackie bought a bag of oranges. she used 3/8 of the oranges to make orange juice. she used 1/3 of the oranges to make a fruit salad. she put 1/8 of the oranges in a bowl on the table. she put 2/12 of the oranges in the refrigerator. a) jackie left more oranges on the table than she put in the refrigerator. b) jackie used fewer oranges to make orange juice than she left on the table. c) jackie put fewer oranges in the refrigerator than she used to make the fruit salad. eliminate d) jackie used more oranges to make a fruit salad than she used to make orange juice.

Mickey needs to cut pieces of ribbon that are each 1 meter long tie onto balloons. if he has 8 pieces of ribbon that are each 1 dekameter long. how many 1 meter pieces of ribbon can he cut

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?