Loan B has the lower interest rate 12%.
The left hand side expression of the given equation is a difference of two squares. The first term, x², is a square of x and the second term, 25 is the square of 5. The factors of the expression are (x - 5) and (x + 5).
(x - 5)(x + 5) = 0
The values of x from the equation above are x = -5 and x = 5.
All you have to do is add, then multiply your total with the total to receive your answer.