Question:
Find the equation of the line whose
(i) slope $=3$ and $y-$ intercept $=5$
(ii) slope $=-1$ and $y$ - intercept $=4$
(iii) slope $=-\frac{2}{5}$ and $y-$ intercept $=-3$
Solution:
(i) Formula to be used: y = mx + c where m is the slope of the line and c is the y - intercept
Here, m = 3 and c = 5.
Hence, y = (3)x + (5)
i.e. y = 3x + 5
(ii) Formula to be used: y = mx + c where m is the slope of the line and c is the y - intercept.
Here, m = - 1 and c = 4.
Hence, y = ( - 1)x + (4)
i.e. x + y = 4
(iii) Formula to be used: y = mx + c where m is the slope of the line and c is the y - intercept.
Here, $m=-\frac{2}{5}$ and $c=-3$
Hence, $y=\left(-\frac{2}{5}\right) x+(-3)$
Or, $5 y=-2 x-3$ i.e. $2 x+5 y+3=0$