Question

If a, b, c are in A.P., then the straight lines ax + by + c = 0 will always pass through point ___________.

Answer 1

Since for ax + by + c = 0
Given a, b, and c are in A.P.
i.e. 2b = a + c
i.e. a − 2b + c = 0
∴ x = 1 , y = −2
i.e. ax + by + c = 0 passes through (1, −2)