137,638+52,091 is 189729.
-4/9 times -5/8 you can cross cancel the 4 and 8 so it makes the problem -1/9 times -5/2 which equals -5/18
The domain of the function is \[A \ge0\] If A is negative we get an imaginary number for the radius. This makes sense because the area of a circle cannot be negative.
