Last month, raul bought 6 used books for $7.50. this month he bought 8 used books for $10.00. what is the constant of proportionality between the cost and the number of books bought?

a. 0.75
b. 1.25
c. 2
d. 2.5

Kevin is an insurance salesman. when he sells a policy, he makes 20 percent of the policy premium (p) up front; then each year the policy is active, he receives 15 percent of the original premium. which equation could be used to figure his total commission on a policy that has been active for five years? c=0.80p c=0.20p + 0.15p c=0.35p + 4(0.15) c=0.95p

If the discriminant if a quadratic equation is 4 which statement describes the roots?

Plz ( true - false) all triangles have interior angles whose measure sum to 90.