Linear Equations
1. [2 Points] 
Write the
slope-intercept form of the equation of the line through the point
(5,−1) that is parallel to the line through the points (-3, 8) and (7, 4).
ANS: __________
2. [3 Points] The sales of a small software
company are a linear function of time. Sales
were $120,000 in 1999 and $180,000 in 2003. If the linear trend continues,
in which year
will the annual sales reach $240,000?
ANS: __________
3. [5 Points] Only four of the following five
points are on the same line. Which point is
not on the line determined by the other four?
ANS: __________
1. [2 Points] Write the
slope-intercept form of the equation of the line through the point
(5,−1) that is parallel to the line through the points (-3, 8) and (7, 4).
|
Solution: |
Slope of line between (-3, 8) and (7, 4) |
The point-slope equation of the line through (5,−1) is |
| |
 |
 |
ANS: 
2. [3 Points] The sales
of a small software company are a linear function of time. Sales were
$120,000 in 1999 and $180,000 in 2003. If the linear trend continues, in which
year will the
annual sales reach $240,000?
| Solution: 
Points:  and
Answer: |
ANS: 2007
3. [5 Points] Only four
of the following five points are on the same line. Which point is not
on the line determined by the other four?
Solution: First,
make all y values have the same denominator (2110). Now, ignore
denominators (easier) and find the slope between any one (fixed) point and each
of the rest. We
select
. If all slopes are different we toss.
If only one slope is different
from the remaining slopes, toss the point which determines the different slope
with.
ANS:
