Respuesta :

Answer:

Its -7

Step-by-step explanation:

1st Triangle

XY=8

YZ=10

ZX=12

Total sum of Triangle

=8+10+12

=20

2nd Triangle

LM=12

MN=15

NL=?

Total sum of triange

LM+MN+NL=Total sum of 1st triangle

=12+15+x=20

=27+x=20

=x=20-27

x=-7