3. Writing Equations of Parallel and Perpendicular Lines
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What do parallel lines have in common?
y=1/3x-4
When lines are parallel, they have the same slope. To help us identify the slope of this line, let's first convert it into slope-intercept form, y= mx+ b, where m is the slope and (0, b) is the y-intercept.
LHS+x=RHS+x
.LHS /3.=.RHS /3.
Write as a difference of fractions
Calculate quotient
With this, we can more easily identify the slope m and y-intercept b.
As we can see we got exactly the same y-intercept as in the given equation. So we can write the equation for the line that is parallel to 3y-x=-12 and passes through (18,2). y= 1/3x- 4