Answer:
Option A is the correct choice.
Step-by-step explanation:
We have been given a graph of angles formed around a line and we are asked to choose the correct option that could be used in step 2 to prove that x equals 30.
![\text{ Given}: m\angle ORP=80^o](https://tex.z-dn.net/?f=%5Ctext%7B%20Given%7D%3A%20m%5Cangle%20ORP%3D80%5Eo)
We can see that angle ORP and angle ORN (3x+10) forms a linear pair as they are adjacent and formed by line PN intersected by line MO.
Therefore, the step 2 to prove that measure of x is 30 will be:
is linear pair of angles and option A is the correct choice.
Let us solve for x.
Since linear pair of angles add up-to 180 degrees, so we can set an equation as:
![m\angle ORP+m\angle ORN=180](https://tex.z-dn.net/?f=m%5Cangle%20ORP%2Bm%5Cangle%20ORN%3D180)
![80+3x+10=180](https://tex.z-dn.net/?f=80%2B3x%2B10%3D180)
![90+3x=180](https://tex.z-dn.net/?f=90%2B3x%3D180)
![90-90+3x=180-90](https://tex.z-dn.net/?f=90-90%2B3x%3D180-90)
![3x=90](https://tex.z-dn.net/?f=3x%3D90)
![\frac{3x}{3}=\frac{90}{3}](https://tex.z-dn.net/?f=%5Cfrac%7B3x%7D%7B3%7D%3D%5Cfrac%7B90%7D%7B3%7D)
![x=30](https://tex.z-dn.net/?f=x%3D30)
Hence proved.