How do you do this question?

In the equations, a and b represent the price per night for a room in hotel a and hotel b, respectively, w weeks after september 1 last autumn. what was the price per night in hotel a when it was equal to the price per night in hotel b? a = 240 − 20w b = 320 − 30w

How do you find principle and simple interest

You have a square piece of cardboard that measures 14 inches on each side. to build a box, you cut congruent squares out of each corner of the cardboard. use the picture to find the area of the cardboard you were used to build the box