What's the value of mn^-1?

Question

f(x)=x²+6x-4

 

If the parabola described above is shifted m units to the right and n units up, the new vertex is (5,-6). What's the value of mn^-1?

Answer 1

y=x²+6x-4=(x+3)²-13

y+13=(x+3)² vertex at (-3,-13) ,

y-(-13-n)=(x-(-3-m))² is this parabola shifted m to right, n up.  New vertex at (5,-6) means that

-13-n=-6 so n=-7, -3-m=5 so m=-8 and equation is y+6=(x-5)²

m/n=8/7