Practice and Problem-Solving Exercises
A Practice
See Problem 1.
Write an equation of each line.
- slope = 3; through (1, 5)
- slope =
5
6
;
5 sixths , semicolon through (22, 12)
- slope =
−
3
5
;
negative , 3 fifths , semicolon through
(
−
4
,
0
)
open negative 4 comma 0 close
- slope = 0; through
(
4
,
−
2
)
open 4 comma negative 2 close
- slope =
−
1
;
negative 1 semicolon through
(
−
3
,
5
)
open negative 3 comma 5 close
- slope = 5; through (0, 2)
See Problem 2.
Write in point-slope form an equation of the line through each pair of points.
-
(
−
10
,
3
)
open negative 10 comma 3 close and
(
−
2
,
−
5
)
open negative 2 comma negative 5 close
- (1, 0) and (5, 5)
-
(
−
4
,
10
)
open negative 4 comma 10 close and
(
−
6
,
15
)
open negative 6 comma 15 close
-
(
0
,
−
1
)
open 0 comma negative 1 close and
(
3
,
−
5
)
open 3 comma negative 5 close
- (7, 11) and (13, 17)
- (1, 9) and (6, 2)
See Problem 3.
Write an equation of each line in standard form with integer coefficients.
-
y
=
1
2
x
−
2
y equals , 1 half , x minus 2
-
y
=
−
7
x
−
9
y equals negative 7 x minus 9
-
y
=
−
3
5
x
+
3
y equals negative , 3 fifths , x plus 3
-
y
=
4.2
x
+
7.9
y equals 4.2 x plus 7.9
See Problem 4.
Find the intercepts and graph each line.
-
x
−
4
y
=
−
4
x minus , 4 y equals negative 4
-
2
x
+
5
y
=
−
10
2 x plus 5 y equals negative 10
-
−
3
x
+
2
y
=
6
negative 3 x plus 2 y equals 6
-
5
x
+
7
y
=
14
5 x plus 7 y equals 14
See Problem 5.
Write and graph an equation to represent each situation.
- You put 15 gallons of gasoline in your car. You know that this amount of gasoline will allow you to drive about 450 miles.
- A meal plan lets students buy $20 meal cards. Each meal card lasts about 8 days.
See Problem 6.
Write the equation of the line through each point. Use slope-intercept form.
-
(
1
,
−
1
)
;
open 1 comma negative 1 close semicolon parallel to
y
=
2
5
x
−
3
y equals , 2 fifths , x minus 3
-
(
−
2
,
1
)
;
open negative 2 comma 1 close semicolon perpendicular to
y
=
−
2
5
x
−
4
y equals negative , 2 fifths , x minus 4
-
(
−
2
,
10
)
;
open negative 2 comma 10 close semicolon parallel to
2
x
−
3
y
=
−
3
2 x minus 3 y equals negative 3
-
(
−
2
,
1
)
;
open negative 2 comma 1 close semicolon perpendicular to
3
x
+
y
=
1
3 x plus y equals 1