It is 54. Draw it out. You will see that DCB - RCB = DCR
The answer would be 11 because the x's 9 doesnt have to move because they're on the same point. If you take 7 away from -7 you get zero. Add 4 to that 7 and you get 11. Make sesnse?
Hope this helped!
The figure is right triangle with base =segment AB = 3 and height = segment AC = 2.
The angle B has tangent, tan (B) = 2 / 3
The angle C, has tangent, tan (C) = 3 / 2
Then, the answer is option C, tan C