Question

The equation of the bisector of the acute angle between the lines $3x-4y+7=0$ and $12x+5y-2=0$ is?

• A. $11x-3y-9=0$
• B. $11x-3y+9=0$
• C. $21x+77y-101=0$
• D. None of these

Answer 1

The correct option is B $11x-3y+9=0$

$\frac{3x-4y+7}{\sqrt{(3{)}^2+(4{)}^2}}=\frac{(-12x+5y-2)}{\sqrt{(12{)}^2+(5{)}^2}}$

$=13(3x-4y+7)=-5(12x+5y-2)$

$39x-52y+91=-60x-25y+10$

$99x-27y+81=0$

$11x-3y+9=0$.