Math 1090
Quiz 3 - Extra credit
February 25th, 2015
Answer the following questions in the space provided. The value of every
question is indicated at the beginning. This is due on Monday, March 9.
No late assignments will be collected. You must turn in this sheet. This
assignment is OPTIONAL and will count as extra credit for Quiz 3.
Name:
UID:
1. Consider the following system of equations.
2x + y + t = a
x+t+w =b
y+z+t=c
x + 2y + z + w = d
x+z+t+w =e
(a) (1 point) Write down the matrix of coefficients A for this system.
(b) (7 points) Find A−1 (augment A with the identity and apply row operations).
(c) (2 points) Take as a, b, c, d, e the last 5 digits of your UID and solve the system
above using A−1 . (For instance, if your UID is 00123456, then you should take
a = 2, b = 3, c = 4, d = 5, e = 6).