please help i dont understand

Answer:
[tex] x = 108 [/tex]
Step-by-step explanation:
A complete turn or a full revolution around a circle corresponds to an angle of [tex]360^\circ[/tex]. In other words, when we traverse the entire circumference of a circle, we've completed one full turn.
For a complete turn, the sum of all the angles around a point should be [tex]360^\circ[/tex].
So,we can write the equation:
[tex] (x-1)^\circ + (x-71)^\circ + 216^\circ = 360^\circ [/tex]
Now, solve for [tex]x[/tex]:
[tex] x - 1 + x - 71 + 216 = 360 [/tex]
Combine like terms:
[tex] 2x + 144 = 360 [/tex]
[tex] 2x = 360-144[/tex]
[tex] 2x = 216 [/tex]
[tex] x = \dfrac{216}{2} [/tex]
[tex] x = 108 [/tex]
So, the value of x is 108°