If the point (3,2) lies on the graph of the equation 5x + ay = 19, then find a.

Ans.

The given linear equation is 5x + ay = 19

∵ the point (3,2) lies on the given graph

∴ we can substitute the point x = 3  and y = 2 in given graph,

∴ 5(3) + a(2) = 19

∴ 15 + 2a = 19

∴ 2a = 19 – 15

∴ 2a = 4

∴ a = 4/2

∴ a = 2