Solving with Matrices

Solve the system of equations:

 $3x\ -\ 3y\ +\ 4z\ =\ -23$  

 $x\ +\ 2y\ -\ 3z\ =\ 25$  
 $4x\ -\ y\ +\ z\ =\ 25$  
Write your answer as (x,y,z) with no spaces, or write no solution.

Solve the system of equations:
 $-x-5y-5z=2$ 
  $4x-5y+4z=19$ 
  $x+5y-z=-20$  
Write your answer as (x,y,z) with no spaces, or write no solution.

The school 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. On the second day the school sold 7 senior citizen tickets, 2 adult tickets and 5 child tickets for $67. The third day the school sold 2 senior citizen tickets, 4 adult tickets, and 2 child tickets for $46. What is the price of one senior citizen ticket?

Andrea sells photographs at art fairs. She prices the photos according to size: small photos cost $10, medium photos cost $15, and large photos cost $40. She usually sells as many small photos as she does medium and large combined. She also sells twice as many medium photos as large. If she sells $300 total, how many small photos did she sell?

Fort Bend Sports Center sold two footballs, three soccer balls, and one softball for $110.50. To another customer they sold one football and three softballs for $41. To a third customer, they sold three footballs, a soccer ball, and two softballs for $92.50. Which matrix equation correctly represents this situation?

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Which matrix is correctly set up to solve the system:

 $3x-3y=-6$ 
  $z=-3x-3y+9$  

 $-4x+5y+z=8$  

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Which set of matrices is not able to be calculated?

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What must be true in order to ADD two matrices?

• They must be square.
• The dimensions must be equal.
• The determinant can't equal 0.
• The column of the 1st must equal the row of the 2nd.

Tags

CCSS.HSN.VM.C.8

Matrices can be multiplied only...

• if the row of the first matrix is equal to the column of the second matrix.

• if the column of the first matrix is equal to the column of the second matrix.

• if the column of the first matrix is equal to the row of the second matrix.

• if the row of the first matrix is equal to the row of the second matrix.

Tags

CCSS.HSN.VM.C.8

What are the dimensions of this matrix?

• 2 x 3
• 3 x 2
• 6 x 1
• 1 x 6

Tags

CCSS.HSN.VM.C.6

CCSS.HSN.VM.C.8