Last month, Mr. Douglas sold 36 of his books. This month, however, he only sold 8 books. What was the percent change in book sales from last month to this month? A decrease of 77.77%
An increase of 3.5%
A decrease of 3.5%
An increase of 77.77%

For problems 29 - 31 the graph of a quadratic function y=ax^2 + bx + c is shown. tell whether the discriminant of ax^2 + bx + c = 0 is positive, negative, or zero.

Julius went on a volunteer trip to centralamerica and took medical supplies with him. he packed a bag with 50 pounds of supplies. he brought pieces of equipment that weighed10 pounds each and bottles of medicine thatweighed pound each prepresents thenumber of pieces of equipment he broughtand b represents the number of bottles ofmedicine he brought then the total weight canbe represented by the equation 10p+b 50.the brought 3 pieces of equipment, how manybottles of medicine did he bring?

Cavaliers principle states that two solids with equal heights and cross-sectional volumes at every level have equal areas.