B+ p= 10.40
b=2x 2.50
Now using substitution method replace b in first equation with value of second equation basically combing the two equations into one do you end up with one variable to solve .
2 x 2.50 +p =10.40
5 + p=10.40
P=$5.40
b =$5.00
The answer is EACH pendant cost $2.70
(You have to divide 5.40 by two )
That will be a line passing through the center and perpendicular to, a line joining the 2 points.