Which is an equivalent ratio to 7: 5? 14: 12 21: 10 21: 15

Select all the correct answers. what is 221,000,000,000,000,000,000 expressed in scientific notation?

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

To solve the system of equations below, pedro isolated the variable y in the first equation and then substituted it into the second equation. what was the resulting equation? { 5y=10x {x^2+y^2=36