Answer:
The width of the field is 35 meters.
Step-by-step explanation:
Recall that the perimeter of a rectangle is given by:

Where <em>w</em> is the width and <em>l</em> is the length of the rectangle.
We know that the perimeter is 150 meters. Thus:

Divide both sides by two:

We are given that the length is five meters longer than the width. So:

Substitute:

Combine like terms:

Subtract five from both sides:

And divide both sides by two. Hence:

Thus, the width of the rectangular field is 35 meters.