Simple elimination only

Math

100

x+y=7

x-y=3

(5,2)

200

2x+y=9

-2x+3y=1

(13/4,5/2) or (3.25,2.5)

300

x + 2y = 8 

x − 2y = 4

(6,1)

400

3x + y = 10

−3x + 5y = 2

(8/3,2)

500

DAILY DOUBLE:

What is the goal when doing the first step of elimination?

Getting a one-step equation. 

is

100

x + y = 0

x − y = 6

(3,-3)

200

4x + y = 11

−4x + 3y = 1

(2,3)

300

DAILY DOUBLE:

What does elimination do? 

Cancels out one variable.

400

x + 3y = 12

x − 3y = 0

(6,2)

500

2x + 2y = 10

−2x + 4y = 6

(7/3, 8/3) or (2.33, 2.67)

the

100

−x + y = 5

x + y = 1

(-2,3)

200

x + 4y = 14

−x + 2y = 2

(10/3, 8/3)

300

2x + y = 7

2x − y = 1

(2,3)

400

3x + 2y = 16

−3x + 4y = 2

(10/3,3)

500

–3x + 2y = –7

–4x + 10y = 20

(5,4)

BEST

100

x + y = 5

2x − y = 4

(3,2)

200

DAILY DOUBLE:

What subject is the best?

LUNCH!!!!

300

5x + y = 21 

−5x + 3y =−1

(16/5, 5)

400

x− y = 2

2x + y = 8

(10/3, 4/3)

500

5x − 5y = 20

–3x + 4y = –8

(8,4)

PERIOD

100

3x + y = 7

3x− y = 11

(3,-2)

200

x + 2y = 3

 −x + 4y = 9

(-1,2)

300

2x + 3y = 13 

−2x + y = 1

(1.25,3.5)

400

x + y = 10 

−x + y = 4

(7,3)

500

–3x + 4y = –11

–6x + 6y = –6

(-7,-8)