Answer
Perimeter of $GHJKL=75$
Work Step by Step
Given pentagon $ABCDE\sim GHJKL$, side $AB$ corresponds to side $GH$.
$\frac{AB}{GH}=\frac{6}{9}=\frac{2}{3}$
The ratio of the sides of the pentagons are 2:3.
The ratio of the perimeters of the pentagons will also be 2:3. So...
$\frac{2}{3}=\frac{50}{x}$
Cross Multiply...
$2x=150$
Divide by 2...
$x=75$ or
The perimeter of $GHJKL=75$