You will need to leave a variable (unknown) in your answer, because you are not given specific values for anything and there is no way to solve. (Your answer will be something called an “algebraic expression.”)
You can use a variable, w, to represent the width of the rectangle. (You could use a variable for length instead, but the way the question is asked it makes more sense to write everything in terms of width.)
”The length is 3 less than the width” means l = w - 3.
Finally, since the formula for area of a rectangle is A = l ⋅ w, we have
A = (w - 3) ⋅ w
That can be rewritten, if you want, as A = w2 - 3w
