1.
Solve the system of equations by elimination.
2
x
+
y
-
z
= 3
x
+
y
+
z
= 5
x
- 2
y
+
z
= 2
A.
(1, 2, 1)
B.
(2, 1, 2)
C.
(1, 1, 2)
D.
(2, 2, 1)
Hint
2.
The equation 2
x
-
y
+ 3
z
= 5 represents _____________
A.
a circle.
B.
a line.
C.
a plane.
D.
none of these.
Hint
3.
Three planes can
A.
intersect at one point.
B.
All of the choices are true.
C.
intersect in a line.
D.
have no points in common.
Hint
4.
Solve the system of equations by substitution.
x
=
z
x
- 2
y
+
z
= 6
2
x
+
y
- 2
z
= 1
What is the value of
x
+
y
+
z
?
A.
11
B.
9
C.
10
D.
8
Hint
5.
If you are solving this system of equations by elimination, which of the following is the best choice for the first step?
2
x
+ 3
y
-
z
= 4
-
x
+
y
+ 2
z
= 3
3
x
+
y
+
z
= 1
A.
both methods are correct
B.
Method II
C.
Method I
D.
neither method is correct.
Hint