Question

When the solution of x^2 - 9x - 9 is expressed as negative 9 plus or minus the square root of r, all over 2, what is the value of r?

A. 117
B. 54
C. 45
D. 9

Answer 1

The value of r in the expression -9 plus or minus the square root of r, all over 2, is 117.

Step-by-step explanation:

To find the value of r in the expression -9 + sqrt(r), we need to solve the quadratic equation x^2 - 9x - 9 = 0. Using the quadratic formula, we have x = (-(-9) +- sqrt((-9)^2 - 4(1)(-9))) / (2(1)). Simplifying the equation further, we get x = (9 +- sqrt(117)) / 2. Comparing this to the given expression, we can see that r = 117. Therefore, the answer is A. 117.