Question

I don't understand this

Answer 1

x=30, 3x-30=60

sum of angles on a straight line =180

therefore, 180-117=63

then, sum of angles in a triangle=180

3x-3+x+63=180

4x+60=180

4x=180-60

4x=120

x=30

3x-30=3(30)-30=60

Answer 2

180 - 117 = 63

so...

(3x -3 ) +(x) + 63 = 180

4x +60 = 180

4x = 180 - 60

4x = 120

x =30