1. Students will write a summary explaining how to use Cramer’s rule.
Applications of Matrices and Determinants (Cramer’s Rule) (Section 7-7)
Essential Question: How do you use Cramer’s rule to solve a system of equations?
Students will write a summary explaining how to use Cramer’s rule.

3. Find the determinant of the matrix.
Example 1

4. Find the determinant of the matrix.
Example 2

5. Find the determinant of the matrix.
Example 3

8. Cramer’s Rule is used when…
The coefficients are large or involve fractions or decimals.
If the denominator equals zero, then there is no solution. no

9. Use Cramer’s Rule to solve the linear system.
5x + 7y = 13
Example 6:
2x – 5y = 13
If solving for y then replace y-column with answer column
y col
x col
Ans
Ans
If solving for x then replace x-column with answer column 13 13 x= y= 5 2 7 -5 7 -5 5 2 5 2 7 -5
Fill in Denominator First
x col
y col
x col
y col

10. Use Cramer’s Rule to solve the linear system.
Example
9x + 4y = -6
3x – 5y = -21

11. Solve using Cramer’s Rule.
Example 7

12. HW #46 pg 556 (3-8 all) pg 567 (15-19 all) pg 575 (171-173 all)