*Have to make sure the square root is around the whole problem
A function for this would be m = 50 + 4.25t. The $50 is the one time thing. We must multiply the tips by 6. 4.25 * 6 = 25.50. 50 + 25.50 is 75.50. Joe would make $75.50 after 6 hours.
You didn't include the actual number in inches.
2x^2 - 8 = 0
2x^2 = 8
x^2 = 8/2 = 4
x = sqrt(4) = 2 or -2