Equation that has x and why does not show direct variation

Will mark brainliest question in the pic.

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

Asquare is dilated by a scale factor of 1.25 to create a new square. how does the area of the new square compare with the area of the original square? a)the area of the new square is 1.25 times the area of the original square. b)the area of the new square is 2.50 times the area of the original square. c)the area of the new square is 1.252 times the area of the original square. d)the area of the new square is 1.253 times the area of the original square.