# Slope-Intercept Form

My partner and I researched the Slope-Intercept Form...

The line must contain a slope, which is found by rise/run. The line will also express the y-intercept, this is the point where the line crosses the y-axis.

The form of this line can simplify graphing and solving for ordered pairs which are solutions to the equation. It is best known to easily identify the slope and y-intercept.

**EXAM****PLE:The equation of the straight line that has slope m = 4**

and passes through the point (–1, –6).

and passes through the point (–1, –6).

Okay, they've given me the value of the slope; in this case, *m* = 4.

They have also given me an *x*-value and a *y*-value for this line: *x* = –1 and *y* = –6.

In the slope-intercept form of a straight line, I have *y*, *m*, *x*, and *b*.

So the only thing I need to figure out is, *b* (which gives me the *y*-intercept).

Steps

1) Write the formula y = mx + b

2) Plug in (Substitute) the value of the slope .

3) Plug in the given (x,y) point.

4) Solve for b, get b all 5)

5) Re-write the formula with the slope and y-intercept.

*y = mx + b(–6) = (4)(–1) + b–6 = –4 + b–2 = b*

*Then the line equation must be "y = 4x – 2".*