<u>Answer:</u>
1) The equation of the line parallel to x-5y=6 and through (4,-2) is 5y = x -14
2) The equation of the line perpendicular to y= -2/5x + 3 and through (2,-1) is 2y = 5x -12
<u>Solution:</u>
<u><em>1) find the equation of the line parallel to x-5y=6 and through (4,-2).</em></u>
Given, line equation is x – 5y = 6
We have to find the line equation that is parallel to given line and passing through the point (4, -2)
Now, let us find slope of the given line.
![\text { Slope }=\frac{-x \text { coefficient }}{y \text { coefficient }}=\frac{-1}{-5}=\frac{1}{5}](https://tex.z-dn.net/?f=%5Ctext%20%7B%20Slope%20%7D%3D%5Cfrac%7B-x%20%5Ctext%20%7B%20coefficient%20%7D%7D%7By%20%5Ctext%20%7B%20coefficient%20%7D%7D%3D%5Cfrac%7B-1%7D%7B-5%7D%3D%5Cfrac%7B1%7D%7B5%7D)
Now, we know that, slope of parallel lines are equal.
So, slope of required line is 1/5 and it passes through (4, -2)
Now, using point slope form
![y-y_{1}=m\left(x-x_{1}\right) \text { where } m \text { is slope and }\left(x_{1}, y_{1}\right) \text { is point on line. }](https://tex.z-dn.net/?f=y-y_%7B1%7D%3Dm%5Cleft%28x-x_%7B1%7D%5Cright%29%20%5Ctext%20%7B%20where%20%7D%20m%20%5Ctext%20%7B%20is%20slope%20and%20%7D%5Cleft%28x_%7B1%7D%2C%20y_%7B1%7D%5Cright%29%20%5Ctext%20%7B%20is%20point%20on%20line.%20%7D)
![y-(-2)=\frac{1}{5}(x-4) \rightarrow 5(y+2)=x-4 \rightarrow 5 y+10=x-4 \rightarrow x-5 y=14](https://tex.z-dn.net/?f=y-%28-2%29%3D%5Cfrac%7B1%7D%7B5%7D%28x-4%29%20%5Crightarrow%205%28y%2B2%29%3Dx-4%20%5Crightarrow%205%20y%2B10%3Dx-4%20%5Crightarrow%20x-5%20y%3D14)
Hence, the line equation is 5y = x -14
<u><em>
2) find the equation of the line perpendicular to y= -2/5x + 3 and through (2,-1)</em></u>
![\text { Given, line equation is } y=-\frac{2}{5} x+3 \rightarrow 5 y=-2 x+15 \rightarrow 2 x+5 y=15](https://tex.z-dn.net/?f=%5Ctext%20%7B%20Given%2C%20line%20equation%20is%20%7D%20y%3D-%5Cfrac%7B2%7D%7B5%7D%20x%2B3%20%5Crightarrow%205%20y%3D-2%20x%2B15%20%5Crightarrow%202%20x%2B5%20y%3D15)
We have to find the line equation that is perpendicular to given line and passing through the point (2, -1)
Now, let us find slope of the given line.
![\text { Slope }=\frac{-x \text { coefficient }}{y \text { coefficient }}=\frac{-2}{5}=-\frac{2}{5}](https://tex.z-dn.net/?f=%5Ctext%20%7B%20Slope%20%7D%3D%5Cfrac%7B-x%20%5Ctext%20%7B%20coefficient%20%7D%7D%7By%20%5Ctext%20%7B%20coefficient%20%7D%7D%3D%5Cfrac%7B-2%7D%7B5%7D%3D-%5Cfrac%7B2%7D%7B5%7D)
Now, we know that, product of slopes of perpendicular lines equals to -1.
So, slope of required line
slope of given line = -1
slope of required line = ![-1 \times \frac{5}{-2}=\frac{5}{2}](https://tex.z-dn.net/?f=-1%20%5Ctimes%20%5Cfrac%7B5%7D%7B-2%7D%3D%5Cfrac%7B5%7D%7B2%7D)
And it passes through (2, -1)
Now, using point slope form
![\begin{array}{l}{\text { Line equation is } y-(-1)=\frac{5}{2}(x-2) \rightarrow 2(y+1)=5(x-2)} \\\\ {\rightarrow 2 y+2=5 x-10 \rightarrow 5 x-2 y=12}\end{array}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Bl%7D%7B%5Ctext%20%7B%20Line%20equation%20is%20%7D%20y-%28-1%29%3D%5Cfrac%7B5%7D%7B2%7D%28x-2%29%20%5Crightarrow%202%28y%2B1%29%3D5%28x-2%29%7D%20%5C%5C%5C%5C%20%7B%5Crightarrow%202%20y%2B2%3D5%20x-10%20%5Crightarrow%205%20x-2%20y%3D12%7D%5Cend%7Barray%7D)
Hence, the line equation is 2y = 5x -12