Since E is the midpoint of DF, DE and EF are two halves of DF. First, let's write down what we know.
DE = 3x + 4
EF = 5x - 2
DE = EF
DE + EF = DF
Now, let's plug our values for DE and EF into our first expression.
3x + 4 = 5x -2
Add 2 to both sides and subtract 3x from both sides.
6 = 2x
Divide both sides by 2
3 = x
Let's plug 3 in for x into DE.
DE = 3x + 4 = 3(3) + 4 = 9 + 4 = 13
DE = EF = 13
We can plug 13 in for DE and EF to get DF
DF = DE + EF = 13 + 13 = 26
