Find the value of

Given: The straight lines 5x – 2y – 9 = 0 and ay + 2x – 11 = 0 are perpendicular to each other.

As the lines are perpendicular to each other, the product of their slopes is equal to –1.

Slope of the first line 5x – 2y – 9 = 0 is m1.

()

Slope of the second line ay + 2x –11 = 0 is m2.

Therefore,

⇒

As the lines are perpendicular m1× m2 = –1

⇒

⇒ a = 5