What is the value of a in the equation 5a-10b=45, when b =3?

Determine whether the set of whole numbers is closed under addition. explain why the set is or is not closed. give an example.

Hillel is juggling flaming torches to raise money for charity. his initial appearance raises $500\$500 $500 , and he raises $15\$15 $15 for each minute of juggling performance. the amount rr r of money hillel raises is a function of tt t , the length of his performance in minutes. write the function's formula.

Asphere has a diameter of 10 in. what is the volume of the sphere?