Answer:
MON= 57
Step-by-step explanation:
5x-23+3x-15=90
8x-38=90
8x=128
x=16
PLUG 16 INTO MON EQUATION
5(16)-23=57
therefore,
MON=57
USE COMPLEMENTARY FOR PROBLEMS LIKE THIS :)))
(btw, assuming that the angle is 90 degrees)
