PAP U4D5 Gaussian Elimination with Matrices

Can the system of equations be solved without performing any further row operations? Why or why not?

• No, you need to continue row operations until you get a row with all zeros on the left side.

• Yes, the last row tells you what z is, you can use that in the second row to find y, and you can use both in the first row to find x.

• Yes, you can tell from these rows that there are infinitely many solutions because one row is a multiple of another row.

• No, you need to continue row operations until you get all zeros and ones on the right side.

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.A.1

Solve!

• (2,7,5)
• (-8,7,5)
• (-8,2,5)
• (-3,2,5)

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.C.8

What is an appropriate first row command to solve this by Gaussian Elimination?

• 2R2 + R2 -> R2

• -2R1 + R2 -> R2

• R3 +R2 --> R3

• 2R1 + R2 --> R2

Tags

CCSS.HSA.REI.C.6

CCSS.HSA.REI.C.8

CCSS.HSA.REI.A.1

Solve!

• (1,1,1)
• (6, -8, 36)
• (6,-8, 20)
• (6,-8,-20)

Tags

CCSS.HSA.REI.C.9

Which of the following is in Row Echelon Form?

• A

• B

• C

• D

Tags

CCSS.HSA.REI.C.8

Solve the system of equations:

• ( -2, 4, 3)

• ( 2, 1, 6)

• No solution

• Infinite solutions

The school that Laura goes to is selling tickets to the annual talent show. On the first day of ticket sales the school sold 4 senior citizen tickets, 2 adult tickets and 5 child tickets for a total of $55. The school took in $67 on the second day by selling 7 senior citizen tickets, 2 adult tickets and 5 child tickets. On the third day the show earned $46 when they sold 2 senior citizen tickets, 4 adult tickets and 2 child tickets. What is the price each of one senior citizen ticket, one adult ticket and one child ticket?

• Adult: $12

  Child: $8

  Senior: $8

• Adult: $6

  Child: $4

  Senior: $5

• Adult: $7

  Child: $5

  Senior: $4

• Adult: $4

  Child: $5

  Senior: $7