Answer:
100>=500-15x
Step-by-step explanation:
He needs at least 100, so it's greater than OR equal to 100. He starts with 500 and goes down 15 each week. The x stands for the amount of weeks that are in the school year. Sorry for the terrible formatting on the greater than or equal to.
80 degrees because it decreases by a half each time so by the time it is E (the fourth letter) it has gotten to 20 so the answer is 160
multiply the height x the length x the width to find the volume of a room (or another 3d object)