
Walter H. answered 05/02/17
Tutor
New to Wyzant
10 Year Veteran Math Teacher
Standard form of a linear equation is Ax+By=C.
To write the equation, first we need to know the slope and a point.
1. Find Slope
Our slope is perpendicular to the that of the points given, so we need to find their slope, and then take the negative reciprocal.
Using their points (1,0) and (5,-2), the slope is:
(Δy)/(Δx)=(-2)/(+4)=-1/2.
Therefore, OUR slope is 2/1=2.
2. Find a Point
Our line must contain the midpoint of (1,0) and (5,-2), so that is the point I want. The midpoint is the (average x, average y)=(3,-1).
3. Write an Equation
We can use slope-intercept (have to find the y-intercept) or just substitute into point-slope form.
m=2
(3,-1)
y-y1=m(x-x1)
Substitute values:
y-(-1)=(2)(x-(3))
Simplify and rewrite in Standard Form:
y+1=2x-6
-2x+1y=-7
-2x+1y=-7
Note: many texts don't want the leading coefficient to be negative, so you might have to multiply everything by (-1)
2x-1y=7