QUIZ 1 OFI

 $y\ =\ -2x\ +\ 1$  

 $2x\ -\ 2y\ =\ 4$  

• 4

• 1

• 6

• 2

 $y\ =\ 2x\ +\ 4$  
 $-5x\ -\ 5y\ =\ -5$  

• -3

• -1

• -5

• -2

Y = 4x - 11

4x - y = 11

• 2

• 0

• 11

• 22

 $-3\ x\ -\ 3y\ =\ -18$  
 $y\ =\ -6x\ +\ 21$  

• 3

• 5

• 9

• 15

 $8x\ -8y\ =\ -24$  
 $3x\ +\ y\ =\ 23$  

• 15

• 20

• 5

• 6

 $-\ 4x\ -\ 2y\ =\ -12$ 

  $2x\ +\ y\ =\ 6$  

• 12

• 1

• 0

• 2

 $5x\ +\ 5y\ =\ 20$  
 $x\ -2y\ =13$  

• -3

• -5

• -2

• -7

WHAT’S A SYSTEM OF EQUATIONS?

• a set or collection of equations that you deal with all together at once

• is an algebraic equation in which each term is either a constant or the product of a constant and (the first power of) a single variable.

• are simpler than non-linear equations, and the simplest linear system is one with two equations and two variables.

• none

 $4x\ -\ 5y\ =\ -23$  
 $2x\ +\ y\ =\ -1$  

• -3

• -5

• -14

• -2

2x + 2y = -10

x = 1 - 3y

• -2

• -3

• 7

• 2