MT210 QUIZ 1
İLKER S. YÜCE
FEBRUARY 1, 2011
Surname, Name:
QUESTION 1. §1.1 LINEAR EQUATIONS IN LINEAR ALGEBRA
Please mark the following statement as TRUE or FALSE:
Every elementary row operation is reversible.
ANSWER 1.
TRUE.
QUESTION 2. §1.1 LINEAR EQUATIONS IN LINEAR ALGEBRA
Determine if the system below is consistent or inconsistent (You don’t need to
find the solution set if it is consistent.)
x1+x2−x3= 0
x1−2x2−19x3= 21
x2+ 6x3= 3.
ANSWER 2.
We need to apply row operations:
1 1 −1 0
1−2−19 21
0 1 6 3
−1R1+R2↔R2
//
1 1 −1 0
0−3−18 21
0 1 6 3
−(1/3)R2↔R2
−1R2+R3↔R3
//
1 1 −1 0
0 1 6 −7
0 0 0 10
Note that we have a row of the form [0 0 0 10]. Therefore, the system above
is inconsistent.
1
