Answer:
A triangle is a total of 180 degrees
So to find what x equals we are going to add up all the degree measurements and make them equal to 180
3x+2x+20+4x-20=180 (combine any like terms on the left)
3x+2x+4x+20-20=180 (3x+2x+4x=9x, 20-20=0)
9x=180 (divide both sides by 9)
x=20
Hope this helps ;)
Explanation: