Write out the prime factor of the following numbers.
a. 15
b. 21
c. 38
d. 42

Will used 20 colored tiles to make a design in art class. 5/20 of his tiles were red. what is an equivalent fraction for the red tiles?

One positive number is 9 more than twice another. if their product is 95, find the numbers

Solve this equation using substitution. {4x + y = −2} {4x + 6y = 44}