1. Form of a linear equation written as y = mx +b
where m is the slope and b is the y-intercept.
Form of a linear equation written as Ax + By = C
where A and B are not both zero.
Point-Slope Form - Form of a linear equation written as
y - y1 = m(x - x1) where m is the slope and x1 and y1 are
a point on the line.
Pearcy Version (Calculator Friendly) y = m(x - x1) + y1

2. m =
y2 - y1
x2 - x1
-1 - 3
2 - 0 -4 2 -2
(0, 3) 3
-2x + 3

3. Pearcy Point-Slope
y = m(x - x1) + y1
Substitute the value for slope
and the x and y coordinates
and you're done! 2 2
(1, -1)
y = 2(x - 1) - (-1)
y = 2(x - 1) +1 -3 2 -3
2x - 3

4. m =
y2 - y1
x2 - x1
1 - (-5)
2 - 0 = 6 2 3
y = mx + b
y = 3x - 5
y = m(x - x1) + y1
y = 3(x - 2) + 1
Since the lines are parallel, m1 = m2 = -2
y = m(x - x1) + y1
y = -2(x - (-2)) + 5
y = -2(x + 2) + 5
y = mx + b
5 = (-2)(-2) + b
5 = 4 + b
1 = b
y = -2x + 1

5. -3
m1 × m2 = -1 -1 1 3 -3 1 3
(3, 2)
y = m(x - x1) + y1
y = 1/3(x - 3) + 2
/3 3 1
1/3 1
1/3x + 1

6. y = mx + b
-2 = -1/4(-8) + b
-2 = 4 + b
-6 = b
y = -1/4x - 6
m1 × m2 = -1
4 × m2 = -1
m2 = -1/4
y = m(x - x1) + y1
y = -1/4(x - (-8)) + (-2)
y = -1/4(x + 8) - 2

7. m =
y2 - y1
x2 - x1
5 - 2
1125 3
375
500
375
500
375x + 500
375x + 500
rent y-intercept

8. intercepts 3 2
(3, 0) (0, 2)

9. $18 3
(6, 18) 6 6

10. The slope is the $650 cost per year and the
y-intercept is the $450 cost to joint the health club.
$18
$2.50
= 7.2 magazines
Since you can't buy 2/10 of a
magazine, you'd have to buy 8
to make the subscription a
better deal.