The expression simplifies as follows:

18 sin(178) cos(178) / sin(356)

Since sin(356) is equal to -sin(4) (since the sine function has a period of 360 degrees), we can rewrite the expression as:

18 sin(178) cos(178) / -sin(4)

Using the trigonometric identity sin(2θ) = 2sin(θ)cos(θ), we can simplify further:

18 (1/2) sin(2*178) / -sin(4)

18 (1/2) sin(356) / -sin(4)

18 (1/2) (-sin(4)) / -sin(4)

18/2

Answer: 9