The little lines crossing the sides of the triangle mean that the 2 sides are identical.
When 2 sides are identical the 2 bottom angles are the same, so 73 and 8y-7 are both 73 degrees. 73 +73 = 146 degrees.
This would mean the third angle ( 6x+4) needs to equal 180 - 146 = 34 degrees.
Now we can find X:
6x+4 = 34
Subtract 4 from each side:
6x = 30
Divide each side by 6:
x = 30/6
X = 5
