a, b,c satisfy
a + b = 3
ac + b = 18
bc + a = 6
Find c.
From ac + b = 18, we can see that
a(c - 1) + (a + b) = 18
a(c - 1) + 3 = 18
a(c - 1) = 15 --- (1)
Similarly,
b(c - 1) + (a + b) = 6
b(c - 1) = 3 --- (2)
Adding (1) and (2) would give the required value.
Ans: c = 7
