we have that
*-------------------------*--------------------------------*
E F G
EF=2x-12
FG= 3x-15
EG=23
we know that
EF + FG = EG
so
[2x - 12] + [3x - 15] = 23 simplify
5x - 27 = 23 add 27 to both sides
5x = 50 divide both sides by 5
x = 10
EF=2x-12-------> EF=2*10-12-------> EF=8
FG= 3x-15------> FG=3*10-15------> FG=15
therefore
the answer part a) is
the value of x is 10
the answer part b) is
the value of EF is 8
the answer part c) is
the value of FG is 15
