The answer is B because its a square so all sides are equal and then you factor
4+8 is 12 so yes it is correct!!!
(5,7) (5,4) (7,4) hope that helps
|DF| = |DE| + |EF|
|DF| = 9x -36
|DE| = 47
|EF| = 3x+10
Substitute:
9x - 39 = 47 + 3x + 10
9x - 39 = 3x + 57 |+39
9x = 3x + 96 |-3x
6x = 96 |:6
x = 16
Put the value of x to the equation |EF| = 3x + 10
|EF| = (3)(16) + 10 = 48 + 10 = 58
Answer: |EF| = 58
