Since the value of r is given (r=2), just switch them => (8*2+1/4)^2 . Then do the multiplication in the brackets: 8*2 and that is 16. Getting (16+1/4)^2. Now just do the integer and fraction: ((64+1)/4)^2 => (65/4)^2 and then use a calculator to figure out what x squared is. In this case we get: 4225/16 or ≈ 264,1 .
