The amount of money you collect after washing x cars at a car wash and asking for donations is represented by the function y = 4x + 21.
Find the domain of the function and determine whether it is discrete or continuous.

At a point on the ground 50 meters from the foot of a tree, the angle of elevation to the tree is 48°. find the height of the tree to the nearest meter.

On a piece of paper, graph y< x+1. then determine which answer matches the graph you drew.

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?