Hi Dayanara,

when you want to write rational function you need to make a fraction.

because of asymptotes denominator will be (x-4)(x+6)

because of x-int nominator will be (x+5)(x-3)

now you have f(x) = K(x+5)(x-3) /(x-4)(x+6)

you need to find K

because of y-int =7

plug in x=0 and f(0) =7 in above function and find k

7 = k(0+5)(0-3)/(0-4)(0+6) K=56/5

as a result f(x) = 56(x+5)(x-3) /5(x-4)(x+6)

I hope it is useful,

Minoo