Question

Write the equation of the line that passes through (-1, 11) and (3, -5)

Answer 1

Answer:

y= -4x+7

Step-by-step explanation:

The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept.

Let's find the gradient of the line first.

$gradient = \frac{y1 - y2}{x1 - x2}$

Using the above formula,

$m = \frac{11 - ( - 5)}{ - 1 - 3} \\ m = \frac{11 + 5}{ - 4} \\ m = \frac{16}{ - 4} \\ m = - 4$

Susbt. m= -4 into the equation:

y= -4x +c

Subst. a coordinate to find c.

When x=3, y= -5,

-5= -4(3) +c

-5= -12 +c

c= 12 -5

c=7

Thus the equation of the line is y= -4x +7.