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 $(1,4)$.
$\left[3Marks\right]$

Answer 1

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 $m$ = $\frac{y_2-y_1}{x_2-x_1}$
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=$\frac{4+2}{1-3}$

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

= $-3$
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Intercept $c=-4$
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Equation of the straight line

$y=mx+c$

$y=-3x-4$

$3x+y+4=0$
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