Answer:
x = 55
Explanation:
We know that triangles add up to 180 degrees, so let's start with that. Keep in mind that "y" will be the third degree of the triangle.
21+34+y = 180
55+y = 180
y = 125
Okay, now we know that the third degree is 125. Also, the line that 125 and x are on is a straight line. All straight lines are 180 degrees. Subtract 180 and 125 to get your answer.
180-125 = 55
So your final answer will be x=55, hope this helped!