Test Review for Matrix

What is the name of each entry of a matrix?

• Row

• Element

• Dimension

• Rectangle

How many columns are in a 5 x 4 matrix?

• 5

• 4

• 20

• 9

Perform the indicated operation

• 
• 
• 
• 
• not possible

How would a scalar multiplication be carried out for a matrix?

• Add the Scalar to every element in the matrix

• Dot product the rows of one matrix with the columns of the other matrix

• Multiply every element with the scalar to create a new matrix

• subtract the elements in the first matrix from the elements of the second matrix

This is an example of a

• System of Quadratic Equations

• Reduced Row Echelon Form

• Augmented Matrix

• A Canine Doing a Backflip

Back-substitute to calculate the solution from the REF Matrix.

• 2, 4, (1/2)

• (-1/5), 4, (1/2)

• (1/2), 2, 1

• (1/5) , 4, (1/2)

Johnny was using Gaussian Elimination to simplify the matrix. What did he do wrong in this step?

• To get a zero for a number you should multiply the same row by its' reciprocal

• If you multiply a number to a row you have to change that row too

• He added the numbers incorrectly

• Nothing. This step was correct.

Jessica is simplifying the matrix using Gaussian Elimination. Did she complete the step correctly?

• No, she should have changed the 2 to a zero and multiplied -2 by R2 and added R1

• No, she wanted to change the 3 to a zero so she should have multiplied R2 and added it to R3

• Yes. When you need a zero you multiply by the number's reciprocal.

• No. Just punch in the calculator. Who cares about Carl Gauss

What is the solution to the augmented matrix?

• (3,6,2)

• (3,-5,3)

• (5,5,3)

• ((5/9), (105/9), (-23/9))

• (4, 3, -1)

• (3, 8, 9)

• All Real Numbers

• No Solution