x = k/y^2 is the equation for this statement
substitute the values for the first x and y to find k, the constant of variation.
4 = k/10^2
4 = k/100 Multiply by 100 to clear the fraction
400 = k
Now substitute the k back in and make a new equation that will find any value of x that fits this scenario
x = 400/y^2
x = 400/4
x = 100
