We know that the area of a rectangle:
A = l * w
Therefore, x³-7x+6 = length * (x+3)
If we want to find the length, we must get this alone on the right side of the equation. We can do this by dividing both sides by the width, which we know is x+3.
Thus, an expression for the length is equal to x³-7x-6/(x+3).
