The missing constant term in the perfect square is 49.
x^2 + 14x + 49
We need a squart root of something to make the factor add up equal to 14x. If it's a perfect square, we could divide 14 by 2, 14/2 = 7, and we multiply 7^2, we get 49, which is a perfect square.
A negative number would be reasonable in the solution of the rate of the investment. It would be reasonable because Johnny started out with $41,745 in his account and ended up with $39,974 which means that the rate has to be negative.
i looked at the table, and since t (which is the x-coordinate in this case) was 0, that means that 5.25 is the y-coordinate and is greater than 5 in the first equation.
