Question

If DF = 9x - 39, find EF.
47
3x + 10
D
E
F

Answer 1

|DF| = |DE| + |EF|

Answer: |EF| = 58

|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

- Amaya