If you input: 1/0.00000001 in a calculator, the result will be a very large number
so as you get closer to zero, the result of 1/x larger until it becomes infinite (or undefined as some people like to call it) at 1/0
10 because 30 divided by 10 equals 3 and 50 divided by 10 equals 5 and 3 and 5 only have a GCF of 1 so 10 is your answer
You solve by useing the formula (b/2) ^2
And your answer is x= 3,1