Find the value of x to the nearest tenth

Find the center of the circle that can be circumscribed about efg with e(4,4) f(4,2) g(8,2)

What is the equivalent fraction for the following fraction using 5 as the multiplier? 1/2

The diameter of the moon is about 3500 km. approximate the surface area of the moon using the formula for the surface area of a sphere, s = 4πr^2. write your answer in scientific notation.