Question

E is the midpoint of DF. If DE=9x and DF=19x-7, what is DF?

Answer 1

Answer:

DF=126 units

Explanation:

E is the midpoint of DF.

$\begin{gathered} DF=2\times DE \\ 19x-7=2(9x) \\ 19x-7=18x \\ 19x-18x=7 \\ x=7 \end{gathered}$

Therefore:

$\begin{gathered} DF=19(7)-7 \\ =133-7 \\ =126 \end{gathered}$