A1: Unit 4 Quiz 1 (Sections 1-3)

^{What is the solution to the system?} 

• (1,1)
• -2
• (1, 2)
• (1, -1)

What is the solution?

• No solution
• (0, 2)
• (0, -4)
• (3, -3)

Solve the system by graphing

y = 2x + 1

y = 4x - 1

• (1,3)

• (-1,-3)

• (-1,3)

• (3,1)

If a system of linear equations has infinitely many solutions, what does this mean about the two lines? 

• Intersecting lines
• Identical line
• Parallel lines

What is the first step in solving a system by Substitution?

• Make sure both equations are in standard form.
• Make sure at least one equation is solved for one variable.
• Make sure both equations are in slope-intercept form.
• Make sure both equations can be solved.

Solve the system by substitution.
 
5x + 4y= −14
y =  −7x  −  15 

• (-2, -1)
• (1, -2)
• (-2, 1)
• (-1, -2)

Solve the system by substitution

x - 3y = -13

4x + 2y = 4

• (1, 4)

• (-1, -4)

• (-1, 4)

• (1, -4)

Solve the system by substitution

y = -2x + 18

y = 8

• (5, 8)

• (-5, 8)

• (2, 8)

• (-2, 8)

Solve the system by elimination. 
−4x − 4y = 0
4x + 4y = 0 

• (−6, −4) 
• Infinite number of solutions  
• (−6, 10) 
• (6, 4) 

Solve the system by elimination

8x + 14y = 4

-6x - 7y = -10

• (4, -2)

• (-2, 4)

• (0, 3)

• (4, -2)