What is –9 – (–13) and how do i solve

Use the radius you found in part i (r=26.8 cm) with the surface area formula below to find the surface area of the sphere. show your work and round your answer to the nearest tenth. the surface area of a sphere: sa = 4πr^2 self note: 3.8.4

If 24 people have the flu out of 360 people, how many would have the flu out of 900. choose many ways you could use proportion that david would use to solve this problem

Can someone me and do the problem plz so i can understand it more better