Math Problem Statement

Jika A = (6 7; 2 3) dan B = (-5; 4), maka hasil perkalian matriks A dan B adalah?

Solution

The problem shown in the image asks for the result of matrix multiplication between two matrices, AA and BB, where:

A=(6723),B=(54)A = \begin{pmatrix} 6 & 7 \\ 2 & 3 \end{pmatrix}, \quad B = \begin{pmatrix} -5 \\ 4 \end{pmatrix}

Matrix multiplication between matrix AA (which is a 2x2 matrix) and matrix BB (which is a 2x1 matrix) is possible, and the resulting matrix will be a 2x1 matrix.

Step-by-Step Solution

To multiply AA and BB, we compute the dot product of each row of matrix AA with matrix BB:

AB=(6723)(54)A \cdot B = \begin{pmatrix} 6 & 7 \\ 2 & 3 \end{pmatrix} \cdot \begin{pmatrix} -5 \\ 4 \end{pmatrix}

First element of the resulting matrix:

(6×5)+(7×4)=30+28=2(6 \times -5) + (7 \times 4) = -30 + 28 = -2

Second element of the resulting matrix:

(2×5)+(3×4)=10+12=2(2 \times -5) + (3 \times 4) = -10 + 12 = 2

Result:

The result of multiplying matrices AA and BB is:

(22)\begin{pmatrix} -2 \\ 2 \end{pmatrix}

This corresponds to the first option on the left in the given choices.


Would you like more details on matrix multiplication or further clarification?

Here are five related questions for practice:

  1. What happens when you multiply two 2x2 matrices together?
  2. How would the result change if matrix BB had different values?
  3. Can you find the inverse of matrix AA, if it exists?
  4. What is the determinant of matrix AA?
  5. How does matrix multiplication differ from element-wise multiplication?

Tip: Always check the dimensions of matrices before multiplying to ensure that the operation is valid.

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Math Problem Analysis

Mathematical Concepts

Matrix Multiplication
Linear Algebra

Formulas

Matrix Multiplication Formula: A(m x n) * B(n x p) = C(m x p)

Theorems

Dot Product in Matrix Multiplication

Suitable Grade Level

Grades 10-12