To solve for this, set up a proportion.
21/40 = x/100.
Cross multiply the fraction's numerators with the denominators;
21 x 100, 40 and x.
2100/40x.
Divide both numbers by 40 to get x.
2100/40 = 52.5
21 is 52.5% of 40.
I hope this helps!
Answer:

Step-by-step explanation:
An ellipse is the locus of a point such that its distances from two fixed points, called foci, have a sum that is equal to a positive constant.
The equation of an ellipse with a center at the origin and the x axis as the minor axis is given by:

Since the distance of the satellite from the surface of the moon varies from 357 km to 710 km, hence:
b = 357 km + 959 km = 1316 km
a = 710 km + 959 km = 1669 km
Therefore the equation of the ellipse is:
