Find
dy/du, du/dx, and dy/dx

y= u^2 , u=4x+7

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

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?

Estimate the area under the curve f(x) = 16 - x^2 from x = 0 to x = 3 by using three inscribed (under the curve) rectangles. answer to the nearest integer.