The length of the rectangular pool is 30m longer than 6 times the width.
Let "x" represent the length of the width, then you can express the dimensions of the pool as follows:

The perimeter of the pool is 1110m, this perimeter was obtained using the formula:

Replace the formula with the expressions determined for the width and length:

From this expression, you can determine the value of x:
-First, distribute the multiplications on the right side of the equation:

-Second, pass 60 to the left side of the equal sign by applying the opposite operation to both sides of it:

-Third, divide both sides of the equation by 14 to determine the value of x:

The width of the pool is w= 75 meters
Now you can determine the length of the pool:

The length of the pool is l=480 meters