I assume you are trying to find the width right?
If so, here's how.These words make it sort of confusing, but try making an equation
Use 2x for twice the width, which is unknown. Subtract three since the length is 3 meters less.
2x-3=18 is your equation. Move over the three by adding. Now you have 2x=18. Divide by 2 on BOTH sides to get your x alone. Your answer should be width= 9 meters.
