a+b=8
b+c=3
subtract the top by the bottom
a-c=5
a-c=5
a+c=5
add top and bottom
2a=10
a=5
now that we know a, we can find b by using the first equation
a+b=8
5+b=8
b=3
we then plug b into the second equation to get
b+c=3
3+c=3
c=0
5*3*0 = 0
abc=0
c=0
