Question

Find the equation for the line on which the point (1, 2) lies are there more than one line possible

Answer 1

let the eqn. of line be 'ax + by + c = 0'
putting points 1,2 in the eqn.
1(x) + 2(y) + c= 0
so, x + 2y + c = 0
is the required eqn.
there is only one unique line which passes through the given point.
Hope it helps.......

Answer 2

let x be 1 and y be 2 then subsituite the value in ax+by+c=0