What is the value of x?

Find an equation (in term of x) of line through the points (-1,3) and (1,4)

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

Determine the number of girls in a math class with 87 boys if there are 25 girls for every 75 boys