7.4 // ELIMINATION (PART III)
3x ­ y = 17
2x + 3y = 15
1
Last, the toughest of all:
3x + 2y = 16
2x + 5y = 7
2
7­5 // SPECIAL SYSTEMS
If after elimination,
you end up with:
Here's the solution:
0 = 4
No solutions (∅)
2x = ­4
One solution
2 = 2
Infinite solutions (∞)
3
When Graphing ...
One solution
Infinite
Solutions
No solutions
4
After "elimination"
which kind is this?
One Sol ∞
3x + 8y = 10
4x ­ 8y = ­10
∅
5
And finally, ...
One Sol ∞
∅
5x + 3y = 1000
5x + 3y = 1000
6
Assignment
HW
#7
pp 454­55
3, 5, 7, 9, 11
and
pp 462­65
7, 13, 20, 24, 28
5
7