x - the width (m)
4x - 7 - the length (m)
136m - the perimeter
The formula of the perimeter of the rectangle: 2a + 2b.
Substitute:
[tex]2\cdot x+2\cdot(4x-7)=136\\\\2x+2\cdot4x-2\cdot7=136\\\\2x+8x-14=136\\\\10x-14=136\ \ \ |+14\\\\10x=150\ \ \ \ |:10\\\\x=15\ m\\\\4x-7=4\cdot15-7=60-7=53\ m[/tex]
Answer: The length = 53m; the width = 15 m.
