We have this equation{a=3ba−3=b+3

(with a is the length and b is the width)

⇒3b−3=b+3

⇒3b=b+6

⇒2b=6

⇒b=3

⇒a=9

So that the rug is 3m wide and 9m long.

We have this equation\(\left\{{}\begin{matrix}a=3b\\a-3=b+3\end{matrix}\right.\)(with a is the length and b is the width)

\(\Rightarrow3b-3=b+3\)

\(\Rightarrow3b=b+6\)

\(\Rightarrow2b=6\)

\(\Rightarrow b=3\)

\(\Rightarrow a=9\)

So that the rug is 3m wide and 9m long.