Answer:
x=32
Step-by-step explanation:
sum of interior angles of a triangle = 180
add up all angles and equate to 180
(4x-13)+(x+18)+15=180
5x=160
x=160/5=32
x+18 = 32+18 = 50
4x-13 = 4x32-13 = 128-13 = 115
add up all to check whether ans = 180; 15+50+115=180
