math
posted by janie .
a=b+c2
a=cd+9
a=bd+11
Based on the system of equations above, what is the value of a?
a) 2
b) 9
c) 10
d) 11
e) 20

can't tell. There are 4 unknowns, but only three equations. Any system where
c = b+2
b+d = 11
will work. For example, the table below shows various values of a
b c d a
1 3 10 2
2 4 9 4
. . .