The product of two numbers is 713. The first number is 9 more than the second number. Which equation can be used to find x, the greater number?

x (x - 9) = 713

x (x + 9) = 713

x2 - 9 = 713

x2 + 9 = 713

Let x = first number and y = second number.

The first statement is expressed as

x*y = 713

The second statement is expressed as

x = y + 9

To find x, use the second equation in terms of y, that is y = x - 9. Then substituting it to the first equation yields

x * (x - 9) = 713