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
21.27*40= Annual premium is 850.8 51% of 850.8 is 433.9 ---> semi annual his quarterly is 26% of 850.8 so 221.2 and finally his monthly premium is 9 percent of 850.8 so it's 76.57
You need to use the cosine for this and this is how you do it.
X=5
Measure of angle BCA= 55
Measure of angle B= 76
