The sum of two numbers is 72. the greater number is 8 more than the smaller number. which equation can be used to solve for the smaller number?

x − (x + 8) = 72
x + (x + 8) = 72
x(x + 8) = 72
x(x − 8) = 72

Onnie is considering doing some long term investing with money that she inherited. she would like to have $50,000 at the end of 30 years. approximately how much money would lonnie need to put into an account earning 6% interest compounded annually in order to meet her goal?