5 pizzas are added to a delivery order x, and now there are 16 in total. how many original orders were there? equation

If the measure of xyz is 81 what is the measure of yz

Adj has a total of 1075 dance and rock songs on her system. the dance selection is 4 times the size of the rock selection. write a system of equations to represent the situation.

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?