Answer:
[tex]EF = 58[/tex]
Step-by-step explanation:
Solving for [tex]x[/tex]:
[tex]DF = DE +EF \\ 9x -39 = 47 +(3x +10) \\ 9x -39 = 47 +3x +10 \\ 9x -39 = 3x +57 \\ 9x -39 +39 = 3x +57 +39 \\ 9x = 3x +96 \\ 9x -3x = 3x +96 -3x \\ 6x = 96 \\ \frac{6x}{6} = \frac{96}{6} \\ x = 16[/tex]
Solving for [tex]EF[/tex]:
[tex]EF = 3x +10 \\ EF = 3(16) +10 \\ EF = 48 +10 \\ EF = 58[/tex]
