Download 5.5 Writing Equations in Point

5.5 Writing Equations in PointSlope Form
What you’ll learn:
1. To write the equation of a line in
point-slope form.
2. To write linear equations in
different forms.
Point-Slope Form
Another form of a linear equation is point-slope
form. This is another way to write an equation
when given a point and the slope or two
points.
Point-Slope Form: y  y1  m( x  x1 )
where ( x1 , y1 ) is a point on the line and m is
the slope.
To change an equation from point-slope to
slope-intercept form, just solve for y
Write the point-slope form of an equation for a
line that passes through each point with the
given slope.
1. (4,7), m=3
3. (-6,3), m=0
2. (-5,-2), m=-1
4. (0,-5), m=½
Standard Form
Standard form of a linear equation is Ax+By=C.
The following conditions must be met in order
for it to be in standard form:
 A, B, and C can’t be a fraction or a decimal
 A must be positive
 x and y must be on one side with the
number with no variable on the other
Write each equation in standard form.
1. y-3=2(x-3)
y-3=2x-6
-2x+y=-3
2x-y=3
2. y-1=-3(x-4)
y-1=-3x+12
3x+y=13
3. y+3=-½(x+12)
y+3=-½x-6
½x+y=-9
x+2y=-18
4. y-6=-5(x-4)
y-6=-5x+20
5x+y=26
Write each equation in slope-intercept
form. (Solve for y)
1. y-3=-2(x+4)
y-3=-2x-8
y=-2x-5
2. y+4=1(x-5)
y+4=x-5
y=x-9
3. y-5=½(x-8)
y-5=½x-4
y=½x+1
4. y+2=0(x-6)
y+2=0
y=-2
Classwork
p. 289
16-48 even