What is the vertex of the quadratic function f(c)=(x-8)(x-2)

Aregression was run to determine if there is a relationship between hours of tv watched per day (x) and number of situps a person can do (y). the results of the regression were: y=ax+b a=-0.662 b=30.418 r2=0.703921 r=-0.839

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?

Pls brainliest will be awarded if answer is correct