Practice Test
Is the following ordered pair a solution to the system of equations?
1.
−5x−y=12
x+4y=9
with
For the following exercises, solve the systems of linear and nonlinear equations using substitution or elimination. Indicate if no solution exists.
2.
1
2
x−
1
3
y=4
3
2
x−y=0
3.
−
1
2
x−4y=4
2x+16y=2
4.
5x−y=1
−10x+2y=−2
5.
x−7y+5z=−
1
4
3x+6y−9z=
6
5
4x−6y−2z=
1
10
x−7y+5z=−
1
4
3x+6y−9z=
6
5
6.
x+z=20
x+y+z=20
x+2y+z=10
7.
5x−4y−3z=0
2x+y+2z=0
x−6y−7z=0
8.
y=
x
2
+2x−3
y=x−1
9.
y
2
+
x
2
=25
y
2
−2
x
2
=1
For the following exercises, graph the following inequalities.
11.
x
2
+
y
2
>4
y<
x
2
+1
For the following exercises, write the partial fraction decomposition.
12.
−8x−30
x
2
+10x+25
13.
13x+2
(3x+1)
2
14.
x
4
−
x
3
+2x−1
x
(
x
2
+1)
2
For the following exercises, perform the given matrix operations.
15.
]+
1
2
[
−6
12
4
−8
]
5[
4
9
−2
3
]+
1
2
[
−6
12
4
−8
]
16.
][
3
−4
1
3
5
10
]
[
1
4
−7
−2
9
5
12
0
−4
][
3
−4
1
3
5
10
]
17.
1
3
1
4
1
5
]
−1
[
1
2
1
3
1
4
1
5
]
−1
18.
|
det|
0
0
400
4,000
|
19.
−
1
2
0
−
1
2
0
1
2
0
1
2
0
|
det|
1
2
−
1
2
0
−
1
2
0
1
2
0
1
2
0
|
20.
If what would be the determinant if you switched rows 1 and 3, multiplied the second row by 12, and took the inverse?
21.
Rewrite the system of linear equations as an augmented matrix.
22.
Rewrite the augmented matrix as a system of linear equations.
For the following exercises, use Gaussian elimination to solve the systems of equations.
23.
x−6y=4
2x−12y=0
24.
2x+y+z=−3
x−2y+3z=6
x−y−z=6
For the following exercises, use the inverse of a matrix to solve the systems of equations.
25.
4x−5y=−50
−x+2y=80
26.
1
100
x−
3
100
y+
1
20
z=−49
3
100
x−
7
100
y−
1
100
z=13
9
100
x−
9
100
y−
9
100
z=99
For the following exercises, use Cramer’s Rule to solve the systems of equations.
27.
200x−300y=2
400x+715y=4
28.
0.1x+0.1y−0.1z=−1.2
0.1x−0.2y+0.4z=−1.2
0.5x−0.3y+0.8z=−5.9
For the following exercises, solve using a system of linear equations.
29.
A factory producing cell phones has the following cost and revenue functions: and What is the range of cell phones they should produce each day so there is profit? Round to the nearest number that generates profit.
30.
A small fair charges $1.50 for students, $1 for children, and $2 for adults. In one day, three times as many children as adults attended. A total of 800 tickets were sold for a total revenue of $1,050. How many of each type of ticket was sold?