Step-by-step explanation:
All the angles in a triangle add up to 180 degrees
x-22 + 3x+19 + x-17 = 180
x+3x+x-22+19-17=180
5x - 20=180
5x=180+20
5x=200
5x/5=200/5
x=40
Angle A= x-22
Substitute x in the question
= 40 - 22
=18
Therefore angle A is 18 degrees
