Equations of straight lines

When working with straight lines, there are often many ways to arrive at an equation. Let's see:

Slope Intercept Form (if you know the slope and where the line crosses the y-axis, use this form) y = mx + b m = slope b = y-intercept (where line crosses the y-axis.)	*Point Slope Form* (if you know a point and the slope, use this form) m = slope = any point on the line.

and...

Find the equation of the line that goes through two points P(x ₁,x₂) and Q(y₁,y₂)
Firts find the slope using
and then use the formula:

Write the slope-intercept form of the equation of the line with the slope 2 that contains the point (-4,-5).

Use the slope-intercept form to find b:
y=mx+b
-5=2·(-4)+b
8-5=b
3=b

Then y=2x+3

Find the equation of the line that goes through these two points P(5,-7) and Q(6,1)

Solution: y= x+