Question

The equation of a line passing through the origin and perpendicular to the line 7x − 3y + 4 = 0 is

Options

• 7x – 3y + 4 = 0

• 3x – 7y + 4 = 0

• 3x + 7y = 0

• 7x – 3y = 0

Answer 1

3x + 7y = 0

Explanation;

Hint:

Slope of the line of 7x – 3y + 4 = 0

= `(-7)/(-3)`

= `7/3`

Slope of its ⊥^r = `(-3)/7`

The line passes through (0,0)

Equation of a line is

y – y₁ = m(x – x₁)

y – 0 = `(-3)/7(x - 0)`

y = `(-3)/7x`

⇒ 7y = − 3x

3x + 7y = 0