Question

Use the given information to write the equation of each line

Passing through (1,-4) and (-2,5)

Answer 1

y = -3x - 1

Explanation:

The slope-intercept form of an equation of a line:

`y=mx+b`

m - slope

b - y-intercept

The formula of a slope:

`m=(y_2-y_1)/(x_2-x_1)`

We have two points (1, -4) and (-2, 5).

Substitute:

`m=(5-(-4))/(-2-1)=(5+4)/(-3)=(9)/(-3)=-3`

Substitute the value of a slope and the coordinates of the point (1, -4) to the equation of a line:

`-4=-3(1)+b`

`-4=-3+b` add 3 to both sides

`-4+3=-3+3+b`

`-1=b\to b=-1`

Finally:

`y=-3x-1`