give a scheme definition that will determine the sum of 30, 31, 30, 15 and bind the identifier days-in-semester to this sum. be as concise as possible.

Which system of linear inequalities is represented by the graph?

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?

Astick 2 m long is placed vertically at point b. the top of the stick is in line with the top of a tree as seen from point a, which is 3 m from the stick and 30 m from the tree. how tall is the tree?