Math Problem Statement

Diketahui persamaan matriks: 2(a 2; -3 1) + (4 -1; 0 b) = (3 2; c 4)(2 d; 1 3). Nilai dari a + b + c + d adalah .....

Solution

The image contains a matrix equation that reads:

2(a231)+(410b)=(32c4)(2d13)2 \begin{pmatrix} a & 2 \\ -3 & 1 \end{pmatrix} + \begin{pmatrix} 4 & -1 \\ 0 & b \end{pmatrix} = \begin{pmatrix} 3 & 2 \\ c & 4 \end{pmatrix} \begin{pmatrix} 2 & d \\ 1 & 3 \end{pmatrix}

We are tasked with finding the values of a+b+c+da + b + c + d.

Step 1: Simplifying the Left Side

First, expand the matrices on the left-hand side.

  1. Multiply the matrix (a231)\begin{pmatrix} a & 2 \\ -3 & 1 \end{pmatrix} by 2: 2(a231)=(2a462)2 \begin{pmatrix} a & 2 \\ -3 & 1 \end{pmatrix} = \begin{pmatrix} 2a & 4 \\ -6 & 2 \end{pmatrix}

  2. Add the matrix (410b)\begin{pmatrix} 4 & -1 \\ 0 & b \end{pmatrix} to the result: (2a462)+(410b)=(2a+4416+02+b)=(2a+4362+b)\begin{pmatrix} 2a & 4 \\ -6 & 2 \end{pmatrix} + \begin{pmatrix} 4 & -1 \\ 0 & b \end{pmatrix} = \begin{pmatrix} 2a + 4 & 4 - 1 \\ -6 + 0 & 2 + b \end{pmatrix} = \begin{pmatrix} 2a + 4 & 3 \\ -6 & 2 + b \end{pmatrix}

Step 2: Simplifying the Right Side

Now, perform matrix multiplication on the right-hand side: (32c4)(2d13)\begin{pmatrix} 3 & 2 \\ c & 4 \end{pmatrix} \begin{pmatrix} 2 & d \\ 1 & 3 \end{pmatrix} Multiply the matrices:

((3×2+2×1)(3×d+2×3)(c×2+4×1)(c×d+4×3))=(6+23d+62c+4cd+12)=(83d+62c+4cd+12)\begin{pmatrix} (3 \times 2 + 2 \times 1) & (3 \times d + 2 \times 3) \\ (c \times 2 + 4 \times 1) & (c \times d + 4 \times 3) \end{pmatrix} = \begin{pmatrix} 6 + 2 & 3d + 6 \\ 2c + 4 & cd + 12 \end{pmatrix} = \begin{pmatrix} 8 & 3d + 6 \\ 2c + 4 & cd + 12 \end{pmatrix}

Step 3: Equating Both Sides

We now have the following equation:

(2a+4362+b)=(83d+62c+4cd+12)\begin{pmatrix} 2a + 4 & 3 \\ -6 & 2 + b \end{pmatrix} = \begin{pmatrix} 8 & 3d + 6 \\ 2c + 4 & cd + 12 \end{pmatrix}

By comparing the elements of both matrices:

  1. 2a+4=82a + 4 = 82a=42a = 4a=2a = 2
  2. 3=3d+63 = 3d + 63d=33d = -3d=1d = -1
  3. 6=2c+4-6 = 2c + 42c=102c = -10c=5c = -5
  4. 2+b=cd+12=(5)(1)+12=5+12=172 + b = cd + 12 = (-5)(-1) + 12 = 5 + 12 = 17b=15b = 15

Step 4: Calculating a+b+c+da + b + c + d

Now, we calculate: a+b+c+d=2+15+(5)+(1)=2+1551=11a + b + c + d = 2 + 15 + (-5) + (-1) = 2 + 15 - 5 - 1 = 11

Thus, the value of a+b+c+da + b + c + d is 11.


Would you like further explanation on any steps? Here are 5 additional questions related to this:

  1. How do you multiply two matrices step by step?
  2. Why does matrix addition require the same dimensions for both matrices?
  3. What is the determinant of a 2x2 matrix?
  4. How would this problem change if the matrices were 3x3?
  5. Can matrix multiplication be commutative, and if not, why?

Tip: Always double-check matrix dimensions before attempting operations to avoid errors.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Matrix Operations
Matrix Addition
Matrix Multiplication

Formulas

Matrix Addition: A + B = C where A, B, C have the same dimensions.
Matrix Multiplication: (AB)ij = Sum of the product of elements from the ith row of A and jth column of B.

Theorems

Properties of Matrix Multiplication
Matrix Equation Solving

Suitable Grade Level

Grades 10-12