Multiply matrices, simplify matrix expressions and solve A + X = B
Grade 11 Math Worksheet - Building Confidence
Circle the best answer, or write your answer on the line.
Milo has matrix A, which is 2 × 3, and matrix B, which is 3 × 4. What size is AB?
- 2 × 4
- 3 × 3
- 4 × 2
- Undefined: A and B are different sizes
Matrix A is 4 × 1 and matrix B is 1 × 3. Pia wants AB. What size is AB?
- 1 × 1
- 4 × 3
- Undefined: A and B are different sizes
- 3 × 4
A is a 3 × 4 matrix and B is a 3 × 2 matrix. What size is AB, the product Tala wants?
- Undefined: A has 4 columns but B has 3 rows
- 3 × 2
- 4 × 3
Read this first
Matrix A
Row 1: 6, -3, -4; row 2: -1, -1, -5. Matrix B: row 1: 2, -5; row 2: 6, 1; row 3: -3, -3. Colored: row 2 of A, (-1, -1, -5), and column 1 of B, (2, 6, -3).
Zee colors row 2 of A and column 1 of B. What is the entry in row 2, column 1 of AB?
Matrix A
Row 1: -2, -5, 5; row 2: 5, -3, 5; row 3: -3, 5, -2. Matrix B: row 1: -2, 5; row 2: 6, 4; row 3: 6, -1. Colored: row 3 of A, (-3, 5, -2), and column 1 of B, (-2, 6, 6).
Jun multiplies row 3 of A by column 1 of B. What is the entry in row 3, column 1 of AB?
Matrix A
Row 1: 4, 2; row 2: 3, 4. Matrix B: row 1: -3, -1; row 2: 1, 6. Colored: row 2 of A, (3, 4), and column 2 of B, (-1, 6).
Kira has colored the row and the column to use. What is the entry in row 2, column 2 of AB?
Row 1: -3, 5; row 2: 4, -2. Matrix B: row 1: 2, 2; row 2: -3, 1. Milo finds one entry of the product AB. What is the entry in row 2, column 1?
Row 1: -8, -8; row 2: 1, -5. Matrix B: row 1: 6, 7; row 2: -7, 8. Jun solves the matrix equation A + X = B. What is the entry in row 1, column 2 of X?
Row 1: 9, 5; row 2: -7, -7. Matrix B: row 1: 1, 2; row 2: 11, -8. Kira needs the matrix X with A + X = B. What is the entry in row 2, column 1 of X?
Row 1: 3, -4; row 2: -3, 6. Matrix B: row 1: 1, 9; row 2: 12, 1. In Luz's puzzle, A + X = B. What number goes in row 2, column 2 of X?