Answer: (-4,5)
Step-by-step explanation:
Rotating 90 deg. counterclockwise maps (x,y) onto (-y,x), so (5,4) maps onto (-4,5).
To solve for the variable
, we have to make it alone. The first thing we do is add
to both sides of the equation:

Now add
to both sides:

Finally, divide both sides by 16 to get the final answer:

Therefore,

Hope this helps!
The answer is C. 30.5% :)