Answer = 67
Step-by-step explanation
#you see the straight line near (2x - 4) ? yeah it totals 180°, so you only need to find the degree of the other side.
#The question already show 90° (L) and 48° so you can get the other side degree by minus 180 with the degree known.
Way to do
180° - 48° - 90° = 42°
#and so you only need find the rest of the degree. The degree of (2x + 4)
180° - 42° = 138°
#So the (2x + 4)° is 138°
2x + 4 = 138
2x = 138 - 4
2x = 134
x = 134 : 2
x = 67