Could be 21. Try replacing function designators with the actual functions.
Both sides need to equal 180 (The side with the 90 degrees measurement and the side with equations). So first subtract 180 from 90

to get the measurement of 5x and you get 90 but we aren't done yet since we need to find x so now we need to divide 5 by 90

and we get 18 which is X.

Now we need to find the measurement of Y. Now both angles on that side together equals 180 so we need this equation.

First, distribute 5(y + 11)

Then you get this equation :

Now, add the two equations together

and you get this equation

Now subtract 45 from both sides

and divide by 9 on both sides

and you get your answer

So

and
The prism of the surface area is 11200
Well, first you should make both sides of the equation to the power of 2.
So, you'll have 7X = 1225, and then X is 175 :)
Have a wonderful day!
120-36 = 84 <==== what he has left
84/120×100% = percentage of what he has left
70% = percentage aka answer.