How can i use models to relate fractions and decimals?

The axis of symmetry for the graph of the function f(x)=1/4^2+bx +10 is x=6. what is the value of b?

Apatient is given 50 mg dose of medicine the medicines effectiveness decreases every hour at a constant rate of 40% what is the exponential decay function that models this scenario how much medicine will be left in the patients system after 2 hours

Credit card a offers an introductory apr of 3.4% for the first three months and standard apr of 15.7% thereafter,