Find a formula for a function that has vertical asymptotes x = 7 and x = 9 and horizontal asymptote y = 7.

Sure, a function that has vertical asymptotes at x = 7 and x = 9 and a horizontal asymptote at y = 7 can be represented by a rational function. The vertical asymptotes suggest that the denominator of the function should be zero at x = 7 and x = 9. This can be achieved by having factors of (x - 7) and (x - 9) in the denominator. The horizontal asymptote at y = 7 suggests that the degree of the polynomial in the numerator and the denominator should be the same, and the ratio of the leading coefficients should be 7.

A possible function that satisfies these conditions is:

f(x) = 7(x - 6) / [(x - 7)(x - 9)]

This function has vertical asymptotes at x = 7 and x = 9 (since the function is undefined at these points) and a horizontal asymptote at y = 7 (since the degree of the numerator and the denominator are the same and the ratio of the leading coefficients is 7).