find the maximum area of a rectangle whose length is 45 less three times it width.

Question

round to the nearest tenth.

Answer 1

l = 3w - 45, l = 3(w - 15)

A = lw

You have two unknowns and only one equation. I don't think you can solve this.

If w = 16, then l = 3

If w= 17, then l = 6

If w = 18, then l = 9

And so on indefinitely.

If w = 15, then l = 0

So, a sort of answer is that w must exceed 15.