## Intermediate Algebra (6th Edition)

The amount of vitamins is modeled by: $y=.149x^2-4.475x+406.478$ We are asked to find the weight of a child who should be receiving 600 micrograms. The equation then becomes: $y=.149x^2-4.475x+406.478-600$ Once we simplify using subtraction, we use the quadratic formula. $$x= \frac{-b \pm \sqrt{b^2-4ac}}{2a}$$ Where b is the coefficient of the term with a variable raised to the first power, a is the coefficient of the squared term, and c is the coefficient of the term without a variable in front of it. This gives the answer: 37.7 pounds