Matrices & Systems Quiz Review

find: B*A

• 47     30
  9     5
• 17     15
  42     35
• 10     25
  7     1
• not possible because rows do not match columns

You can multiply a 2X3 matrix by which matrix?

• 2X2
• 2X12
• 3X12
• 2X3

What are the dimensions of this matrix?

• 3x1
• 1x3
• 3x3
• 1x1

What is a₂₃

• 14

• 4

• 1

• 3

What is the dimension of this matrix?

• 2 x 3

• 3 x 2

• 6 x 1

• 1 x 6

Multiply using the Dot Product

• 
• 
• 
• 

Solve by elimination 
-2x + 6y = 16
-4x  - 3y = 2

• (2,2)
• (-2, -2) 
• (-2,2)
• (2,1)

Solve for x and y by using the substitution method.

3x + 2y = 16

y = -7x + 19

• (-2,5)

• (-2,-5)

• (2,-5)

• (2,5)

These matrices are being multiplied. Determine the dimension/size of the new matrix. 

• Can't multiply them
• 4  x  2
• 3  x  3
• 4  x  3

Find -3A+B

• 0     -10

  -20      1 

• 8     10

  8     1

• -24     -30

  24     3

• can't add two together because the rows dont match columns