6.11 Solving Systems by Elimination #3
6.11 Solving Systems by Elimination #3 Video Notes
1. A particular store was having a sale on certain shirts and tank tops. Brooklyn got 3 shirts and 2 tank tops for $68.
Savannah got 4 shirts and 7 tank tops for $140.50. How much does each shirt cost and how much does each tank
top cost?
2. 3x – 4y = 18
3.
2x – 8y = 4
Solution (
,
3x + 5y = 21
-8x - 6y = -34
)
Solution (
,
)
6.11 Solving Systems by Elimination #3
Bell work:
Describe the mistake the person made when solving (if any).
1. x – 6y = -5
x – 5y = 7
2. 5x + 2y = -8
-2x – 3y = -12
x – 6y = -5
-1(x – 5y = 7)
3(5x + 2y = -8)
2(2x – 3y = -12)
x – 6y = -5
-1x - 5y = -7
_____________
-11y = -12
y = 1.09
15x + 6y = -24
4x – 6y = -24
_____________
19x = 0
x=0
3. x = 4y + 7
2x – 3y = -12
2x – 3(4y + 7) = -12
2x – 12y - 21 = -12
-10x - 21 = -12
+ 21
+21
-10x = 9
x = -0.9
4. Gerry got 3 funnel cakes and 2 cotton candies at the fair for $18.75. Henry bought 2 funnel cakes and a cotton candy
for $11.50. How much are funnel cakes?
6.11 Solving Systems by Elimination #3
6.11 Solving Systems by Elimination #3 In Class
1. -10x + 7y = 11
-5x + 3y = 19
Solution (
,
2.
)
7x – 12y = -22
5x – 8y = -14
Solution (
,
)
3. Bill bought 2 chicken sandwiches and 3 bowls of vegetable soup for $16.50. Sam bought 1 chicken sandwich and
2 bowls of vegetable soup for $9.50. What was the cost of each?
4. 7x – 14y = -133
5x + 2y = 1
Solution (
,
5.
)
-40x + 4y = 0
30x + 18y = -42
Solution (
,
)