See56.7 cause it is the correct one to the 20th
your answer is the first one, MNO is similar to GHK
the sum of the interior angles of a triangle is 180°
MNO
180 - 22 - 79 = 79° (angle N)
GHK
180 - 79 - 79 = 22° (angle K)
From here you see that they have the same angles, so they are similar.
Answer:

Step-by-step explanation:
I will work with radians.
![$\frac {\cos^2 \left(\frac{\pi}{2}-x \right)+\sin(-x)-\sin^2 \left(\frac{\pi}{2}-x \right)+\cos \left(\frac{\pi}{2}-x \right)} {[\sin(\pi -x)+\cos(-x)] \cdot [\sin(2\pi +x)\cos(2\pi-x)]}$](https://tex.z-dn.net/?f=%24%5Cfrac%20%7B%5Ccos%5E2%20%5Cleft%28%5Cfrac%7B%5Cpi%7D%7B2%7D-x%20%5Cright%29%2B%5Csin%28-x%29-%5Csin%5E2%20%5Cleft%28%5Cfrac%7B%5Cpi%7D%7B2%7D-x%20%5Cright%29%2B%5Ccos%20%5Cleft%28%5Cfrac%7B%5Cpi%7D%7B2%7D-x%20%5Cright%29%7D%20%7B%5B%5Csin%28%5Cpi%20-x%29%2B%5Ccos%28-x%29%5D%20%5Ccdot%20%5B%5Csin%282%5Cpi%20%2Bx%29%5Ccos%282%5Cpi-x%29%5D%7D%24)
First, I will deal with the numerator

Consider the following trigonometric identities:




Therefore, the numerator will be

Once



Now let's deal with the numerator
![[\sin(\pi -x)+\cos(-x)] \cdot [\sin(2\pi +x)\cos(2\pi-x)]](https://tex.z-dn.net/?f=%5B%5Csin%28%5Cpi%20-x%29%2B%5Ccos%28-x%29%5D%20%5Ccdot%20%5B%5Csin%282%5Cpi%20%2Bx%29%5Ccos%282%5Cpi-x%29%5D)
Using the sum and difference identities:





Therefore,
![[\sin(\pi -x)+\cos(-x)] \cdot [\sin(2\pi +x)\cos(2\pi-x)] \implies [\sin(x)+\cos(x)] \cdot [\sin(x)\cos(x)]](https://tex.z-dn.net/?f=%5B%5Csin%28%5Cpi%20-x%29%2B%5Ccos%28-x%29%5D%20%5Ccdot%20%5B%5Csin%282%5Cpi%20%2Bx%29%5Ccos%282%5Cpi-x%29%5D%20%5Cimplies%20%5B%5Csin%28x%29%2B%5Ccos%28x%29%5D%20%5Ccdot%20%5B%5Csin%28x%29%5Ccos%28x%29%5D)
![\implies [p+4] \cdot [p \cdot 4]=4p^2+16p](https://tex.z-dn.net/?f=%5Cimplies%20%5Bp%2B4%5D%20%5Ccdot%20%5Bp%20%5Ccdot%204%5D%3D4p%5E2%2B16p)
The final expression will be

The first thing we must do for this case is to define variables.
We have then:
x = Multiple-choice questions
y = short-answer questions
We write the following system of equations:
2x + 4y = 80
x + y = 25
Solving the system of equations we have:
x = 10
y = 15
Answer:
there are 10 multiple-choice questions