Question

Find equation of the line perpendicular to the line $x – 7y + 5 = 0$ and having x intercept 3.

Answer 1

The given equation of line is
$x–7y+5=0$
or $y = \frac{1}{7}x +\frac{ 5}{7}$, which is of the form $y = mx + c$

∴Slope of the given line=$\frac{1}{7}$
The slope of the line perpendicular to the line having a slope of $\frac{1}{7}$ is $m=\frac{-1}{(\frac{1}{7})} = -7$
The equation of the line with slope -7 and x-intercept 3 is given by
$y = m (x \- d)$
$⇒ y = -7 (x - 3)$
$⇒ y = -7x + 21$
$⇒ 7x + y = 21$