Answer:
x = 25
Step-by-step explanation:
Angle 1 and the angle opposite from Angle 1 (the angle that's 68°) are vertical angles.
What are vertical angles, you ask?
According to the Oxford dictionary, vertical angles are each of the pairs of opposite angles made by two intersecting lines.
For example, take the letter X. The letter X has two lines that intersect to form 4 angles. The top and bottom angles are a pair of vertical angles. So are the left and right angles.
Vertical angles are always congruent.
(This is VERY important to know! It will help you solve many types of geometry problems!)
m1 is 3x - 7. Because Angle 1 and the angle that's 68° are vertical angles, that means they are equal to each other.
Therefore: 3x - 7 = 68.
Now, you can solve for x to get x = 25.
Hope this helps!
