Answer:
x=12.2
<LMN=49.6
<SML=40.4
Step-by-step explanation:
3x+13+7x-45=90
3x+7x+13-45=90
10x-32=90
10x=122
3(12.2) + 13
36.6+13
49.6
7(12.2) -45
85.4-45
40.4
49.6+40.4=90
