Find the value of x.

Answer:
x = 30
Step-by-step explanation:
We know that the angle is a right angle, which is equal to 90. So in order to see what the equation is equal to, we have to subtract 81 from 90.
90 - 81 = 9
With the answer we get, we can now begin to solve for x.
2x - 51 = 9, add 51 to both sides
2x = 60, divide 60 by 2 to get x
x = 30
Now, to check your work, plug 30 into the equation.
2(30) - 51
60 - 51 = 9
hope this helps!! :]