Question

Graph a line with -2 slope passing through (2,-5)

Answer 1

Explanation:

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

m - slope

b - y-intercept (0, b)

We have the slope m = -2.

Substitute to the equation:

`y=-2x+b`

Substitute the coordinates of the given point (2, -5) → x = 2, y = -5

`-5=(-2)(2)+b`

`-5=-4+b` add 4 to both sides

`-5+4=-4+4+b\\\\-1=b\to b=-1`

The equation of a line:

`y=-2x-1`

Two points are enough to draw a straight line.

We have (2, -5) and the y-intercept b = -1 ⇒ (0, -1).

Mark them on a coordinate system.

`\bold{METHOD\ 2:}`

Mark the given point on the coordinate system.

We know:

`slope=(rise)/(run)`

`slope=-2\to(rise)/(run)=-2\\\\-2=(2)/(-1)`

Thereofre

rise = 2 (2 units up)

run = -1 (1 unit to the left)