Question

A line passes through 2, -1 and 4, 5 what is the equation

Answer 1

y1 - y2 / x1 - x2

-1 - 5 / 2 - 4

-6/-2

3

y = mx + b

-1 = 3(2) + b

-1 = 6 + b

-7 = b

y = 3x - 7

Hope this helps! ;)

Answer 2

Answer:

The equation is $3x -y =7$

Solution:

Let us assume that the $(x_1, y_1) = (4,5)$ and $(x_2, y_2) = (2,-1)$

The slope of the line m is $=\frac{y_2-y_1}{x_2-x_1}=\frac{-1-5}{2-4}=\left(\frac{6}{2}\right)=3$

We know the equation of a line at a given point $(x_1,y_1) is (y-y_1) = m(x-x_1)$

Let me take the point (4,5) here,

So the equation of the line is  

$(y-5)=3 \times(x-4)$

$y-5=3 x-12$

$3x-12 - y+5 = 0$

$3x -y -7 =0$

$3x -y =7$

So, the equation is $3x-y =7$