Question

plzzz solve b part.....request

Answer 1

When lines are perpendicular then
product of line slope is equal to zero . Now,
3x-5y=7 line first
And it slope (say m1) = 5/3
4x+ay+9=0 line second
And it slope ( say m2) = - a/4
now apply rule then,
m1 × m2 = 0
5/3 ×-a/3 = 0
-5a/9 = 0
a= 0

Answer 2

If two lines are perpendicular then

Product of their slopes = -1

 

Hence

(3/5) *(-4/a) = -1

 

-12/5a = -1

a = 12/5