by moving to the right by Δy= 4 units and upward by Δx= 3 units. The slope is
therefore
m=Δx/Δy
= 3/4
Remember that the slope of a line is the ratio of a change in the dependent variable to the
change in the independent variable. That means the slope is now Δx/Δy, not Δy/Δx. We
have determined the slope and the x-intercept for line L*, so we can write its SI equation as
x= (3/4)y− 3
- In part D of Fig. B-8, line M* passes through (−2, 0) and (0, −3). The x-intercept is −3.
When we go from (−2, 0) to (0, −3), we move to the right by Δy= 2 units and upward
by Δx=−3 units (the equivalent of downward by 3 units). The slope is therefore
m=Δx/Δy
=−3/2
(0,4)
(0,–2)
x
y
LM
(–3,0)
(0,4)
(0,–2)
x
y
(–3,0) LM
(0,4)
(0,–2)
x
y
LM(–3,0)
A B
C D
Each axis
increment
is 1 unit
M*
L*
(0,–3)
(4,0)
(–2,0)
x
y
Figure B-8 Illustration for the solutions to Probs. 4 through 7 in
Chap. 17. (The rotated and reversed characters are
not typos! The text explains this.)
Chapter 17 647