So let's simplify the equation first.
9x + 12 - 5 = ax + b
9x + 7 = ax + b
9x - ax - b = 7
Alright now plug in the numbers for each option.
I don't feel like doing all of them but I did A (one solution) and B (no solution because the two 9x's cancel out).
For this case we must find an expression equivalent to:
![\sqrt [7] {x} * \sqrt [7] {x} * \sqrt [7] {x}](https://tex.z-dn.net/?f=%5Csqrt%20%5B7%5D%20%7Bx%7D%20%2A%20%5Csqrt%20%5B7%5D%20%7Bx%7D%20%2A%20%5Csqrt%20%5B7%5D%20%7Bx%7D)
By definition of properties of powers and roots we have:
![\sqrt [n] {a ^ m} = a ^ {\frac {m} {n}}](https://tex.z-dn.net/?f=%5Csqrt%20%5Bn%5D%20%7Ba%20%5E%20m%7D%20%3D%20a%20%5E%20%7B%5Cfrac%20%7Bm%7D%20%7Bn%7D%7D)
So, rewriting the given expression we have:

To multiply powers of the same base we put the same base and add the exponents:

Answer:
Option 1
Diameter = 10.0002 inches, or 10 inches since were rounding to the nearest whole number.