Find the Percent, Round to the nearest tenth of a percent, if necessary. (show work) I WILL GIVE BRAINLIEST

9.) Difference of 15 and 21 = |15 - 21|/((15 + 21)/2) = 6/18 = 0.33333333333333 = 33.333333333333%

21 is a 40% increase of 15.

10.) Difference of 60 and 24 = |60 - 24|/((60 + 24)/2) = 36/42 = 0.85714285714286 = 85.714285714286%

24 is a 60% decrease of 60.

Step-by-step explanation:

c

-by-step explanation:

it would be c

in geometry, parallel lines are lines in a plane which do not meet; that is, two lines in a plane that do not intersect or touch each other at any point are said to be parallel. by extension, a line and a plane, or two planes, in three-dimensional euclidean space that do not share a point are said to be parallel.