Question 1058603
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<pre>
Since the angles are vertical, they are congruent.

So, their measures are the same:

2x + 15 = 5x - 15,  or

15 + 15 = 5x - 2x,  or

30 = 3x,

x = {{{30/3}}} = 10.

<U>Answer</U>.  x = 10 degrees.
</pre>

On vertical angles see the lesson

&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;- <A HREF=http://www.algebra.com/algebra/homework/Angles/Vertical-Angles-.lesson>Vertical angles</A> 

in this site. It is one of the basic notions of the elementary geometry.