Question

Find the equation of a straight line whose y intercept is $-4$ and is parallel to the line joining the points $(3,-2)$ and $(1,4)$.

• A. x + 3y + 4 = 0
• B. 3x + y - 3 = 0
• C. x + 3y - 3 = 0
• D. 3x + y + 4 = 0

Answer 1

The correct option is D

3x + y + 4 = 0

An equation of the straight line whose slope is $m$ and intercept on the y-axis is $c$

$y=mx+c$

Slope of required line is same as the slope of the parallel line

Slope parallel line $m$ = $\frac{y_2-y_1}{x_2-x_1}$

=$\frac{4+2}{1-3}$

= $\frac{6}{-2}$

= $-3$

Intercept $c=-4$

Equation of the straight line

$y=mx+c$

$y=-3x-4$

$3x+y+4=0$