The vertex form equation is y = a(x-h)^2+k
Lets substitute our given information.
y = a(x-1)^2+5
Now, lets put in the coordinate it needs to pass through.
8 = a(2-1)^2 + 5
8 = a + 5
a = 3
Now, lets make the equation now that we know a.
y = 3(x-1)^2+5
Hope this helps!