Share

# If the Straight Lines 3x – 5y = 7 and 4x + Ay + 9 = 0 Are Perpendicular to One Another, Find the Value of A. - ICSE Class 10 - Mathematics

#### Question

If the straight lines 3x – 5y = 7 and 4x + ay + 9 = 0 are perpendicular to one another, find the value of a.

#### Solution

3x - 5y = 7

=> 5y = 3x - 7

=> y = 3/5 x - 7/5

⇒ Its slope = 3/5

4x + ay + 9 = 0

⇒ ay = -4x - 9

=> y = (-4)/a x - 9/a

⇒ Its slope = (-4)/a

Since lines are perpendicular to each other,

3/5 xx (-4)/a = -1 => 3/5 xx 4/a = 1 => 4/a =    5/3

=> a = (4xx3)/5 = 12/5

Is there an error in this question or solution?

#### APPEARS IN

Solution If the Straight Lines 3x – 5y = 7 and 4x + Ay + 9 = 0 Are Perpendicular to One Another, Find the Value of A. Concept: Equation of a Line.
S