Let the width be x m, then the length is 2x-7 m.
If the length is decreased by 1m, then new length is 2x-7-1=2x-8 m.
If the width is decreased by 4 m, then new width is x-4 m.
Find the perimeter of new recangle:
[tex]P_{new}=2x-8+x-4+2x-8+x-4=6x-24.[/tex]
The perimeter of new rectangle is 66 m, then
[tex]6x-24=66,\\\\6x=66+24,\\\\6x=90,\\\\x=15.[/tex]
Therefore, old width was 15 metres and old length was 2·15-7=23 metres.
Answer: original width: 15 metres, original length: 23 metres
