PLS HEL If the rate of books and cost is different per each book, is that proportional or nonproportional?

One of the complementary angles is 4 degrees mor than the other. find the angles (recall that complementary angles are angles whose sum is 90 degrees.) which of the following can not be used to solve the problem if x represents one of the angles? a. 2x-4=90 b. 2x+4=90 c. x+4=90

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.

Jack brought 12 pet monkeys. if each monkey cost $45.99, how much money did he spend in all?