Question

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

Answer 1

5x + ay = 19
(x, y) = (3, 2)
The point (x, y) lies on the graph of the equation; hence it satisfies the equation.
Substitute x = 3 and y = 2 in the given equation,
We get
5(3) + a(2) = 19
⇒ 15 + 2a = 19
⇒2a = 19 - 15
⇒ 2a = 4
⇒ a= 4/2 = 2

Therefore the value of a is 2.