How old was lisa x years ago if she is now 13?

which expression represents this?

x + 13
x - 13
13 - x

Quick! what is the area of this trapezoid?

Li buys supplies so he can make and sell key chains. he begins to make a profit only after he sells 4 key chains. what point on the graph makes the most sense in this situation?

Erinn wrote the equation –5x + 4y = 32 to represent her hourly wage (y) and how this wage has changed during each year that she worked at a company (x). what is the rate of change in erinn's hourly wage per year?