Gaussian Elimination

A _____ is a rectangular arrangement of numbers.

• matrix
• dimension
• coefficient
• system

A matrix derived from a system of linear equations is the _____ _____ of the system.

• augmented matrix
• constant matrix
• linear matrix
• coefficient matrix

When an element is missing in an equation, what value must go into the matrix for it?

• 1

• -1

• 0

• NA

Which row command is an appropriate next step?

• 7R2 + R3 -> R3

• -7R1 + R3 -> R3

• 7R3 -> R3

• -7R2 + R3 -> R3

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

What is the value of y?

• 3

• 7

• -1

• 2

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

Which rule is not correct for Gaussian elimination?

• Multiply rows by constant.

• Add/Subtract rows with rows.

• Add/Subtract a number to a row.

• Swap rows

Which of the following is in Row Echelon Form?

• A

• B

• C

• D

Given the matrix below, which numbers do we want to make 1s?
5x + 2y = -1
3x + 7y = 11

• 5 and 3
• 5 and 11
• 5 and 7
• 5 and -1