If the graph of an equation is symmetric with respect to the y-axis and 6 is an x-intercept, name another x-intercept

-6 because for every value (x,y) there is another value (-x,y) so for the value (6,0) there must also be a value (-6,0). That is what the definition of y-axis symmetry is, it is also known as being an "even" function if it has this type of symmetry. Look at the graph of y=(x^2)-36 to see how this works.

It equals 1373.5 that’s the solution