1. Percent of Crop Grown in Each Country
Matrices
Percent of Crop Grown in Each Country
Wheat Rice Corn
China
India
CIS
USA

2. A matrix is a rectangular arrangement of numbers in rows and columns.
row x column
2 x 3 matrix
2 Rows
Entry (ies)
1, 2 = -1
3 Columns

3. Systems of equations as matrices
x + 3y + z = 1
x + 5y + 2z = – 1
2x + 6y + 3z = 2 or

4. Solving a matrix equation
coefficient matrix
ax = b
inverses acted upon each other yield the identity element – they cancel each other
a-1ax = a-1b
x = a-1b
We simply have to multiply by the inverse of the coefficient matrix.

5. Using Graphing Calculator to solve Matrix Equation

8. x + 3y + z = 1
x + 5y + 2z = – 1
2x + 6y + 3z = 2
(4, -1, 0)

9. w + 2x + y – z = – 6 2w – 2x +y + 2z = 8 – w + x – 2y + 3z = 11
4 x 4 matrix
4 x 1 matrix
(1, -1, -2, 3)

10. assignment
page 166/