a rectangular deck has a area of 320 ft squared. the length of the desk is 4 feet longer than the width. find the dimensions of the desk. Solve by completing the square.
Distribute the multiplication over addition and move all to the left side. w^2 +4w-320=0 (w-16)•(w+20)=0 yet, The product of two things is 0 if one is 0 or both are 0 so w-16=0 so w=16 and w+20=0 so w= -20
Now the width or length could not be negative so we discard the solution w=-20.
