MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 8
WING HONG TONY WONG
2.3 Systems of linear equations: underdetermined and overdetermined
systems
Example 1. (2.3.16) Solve the system of linear equations using the Gauss-Jordan elimination
MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 12
WING HONG TONY WONG
2.5 Multiplication of matrices
Just like matrix addition, where A + B can be dened if and only if A and B have the
same sizes, matrix multiplication AB can be dened on
MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 13
WING HONG TONY WONG
2.6 The inverse of a square matrix
The square matrices
1000
100
10
0 1 0 0
1,
, 0 1 0,
0 0 1 0, . . .
01
001
0001
are called the identity matrix of order n, denote
MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 16
WING HONG TONY WONG
3.1 Graphing systems of linear inequalities in two variables
Recall that if we are given a linear equation
ax + by = h,
the way to graph it is to nd the slope a and th
MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 3
WING HONG TONY WONG
2.1 Systems of linear equations: an introduction
Example 1. Determine whether each system of linear equations has one and only one
solution, innitely many solutions, or
MAT 121
MATHEMATICS FOR BUSINESS AND INFORMATION SCIENCE
LECTURE 1
WING HONG TONY WONG
2.1 Systems of linear equations: an introduction
Recall from our algebra knowledge that ax + by = h, where a and b are not both 0,
represents a straight line on a recta