Answer:
The height of the lighthouse is 
Step-by-step explanation:
Let
h -----> the height of the lighthouse
we know that
The tangent of angle of 68 degrees is equal to divide the height of the lighthouse by the horizontal distance from the buoy to the base of lighthouse
so

Solve for h

0.333.... as a fraction is 1/3.
The answer to your problem is 11
6n+1 = 25
subtract 1 from each side
6n+1-1 = 25-1
6n = 24
divide each side by 6
6n/6 = 24/6
n =4