Answer:
Width, RS = 5x - 7 m
Step-by-step explanation:
[tex]perimeter \: qrst \: = \: perimeter \: lmnp \\ let \: the \: width \: of \: rs \: and \: qt \: as \: y \\ 2(2x + 9) + 2y = 14x + 4 \\ 4x + 18 + 2y = 14x + 4 \\ 2y = 14x - 4x + 4 - 18 \\ 2y = 10x - 14 \\ y = \frac{10x - 14}{2} \\ y = 5x - 7[/tex]
