The constant is 6. A constant is just the number on its own. Quadratics follow the form f(x) = ax^2+bx+c. The c is the constant.
Mia would have to work 26.1 hours (approx. 26) to earn $124.00
4.75x=124
divide 4.75 by 4.75 and divide 124 by 4.75
x=26.1
