The equation of this type of line is y = kx. what is special about k?

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

Two lines parallel to the same plane are parallel to eachother

Solve the system of equations y= 3/2 - 1, -x+ y =-3