tolong dengan rumusnya

180° = (2x+15)+6x+(5x-30)
= 2x+6x+5x+15-30
=13x-15
13x. = 180+15
x = 195/13 = 15


2x + 15 = 2.15+15= 45
6x = 6.15 = 90
5x-30 = 5.15-30 = 45

good luck ;-) follow .. be a the best