Question

Difficulty: EasyMatrices and Matrix Operations

Let matrix X=[5321]X = \begin{bmatrix} 5 & -3 \\ 2 & 1 \end{bmatrix} and matrix Y=[1423]Y = \begin{bmatrix} 1 & 4 \\ -2 & 3 \end{bmatrix}. If Z=XYZ = X - Y, what is the value of the element in the first row and second column of ZZ?

Answer: -7

Answer

The correct answer is 7-7.
To find the element in the first row and second column of matrix Z=XYZ = X - Y, we subtract the element in the first row and second column of matrix YY from the corresponding element in matrix XX. The element in the first row and second column of XX is 3-3, and the element in the first row and second column of YY is 44. Subtracting these values gives 34=7-3 - 4 = -7.

Step-by-Step Solution

1
Identify the elements in the first row and second column for both matrices.
x1,2=3x_{1,2} = -3 and y1,2=4y_{1,2} = 4
To find the element in the first row and second column of the resulting matrix ZZ, we must use the corresponding elements from matrices XX and YY.
2
Subtract the element of YY from the element of XX.
34=7-3 - 4 = -7
Since Z=XYZ = X - Y, each element zi,jz_{i,j} of the resulting matrix is calculated as xi,jyi,jx_{i,j} - y_{i,j}.

Key Concept

Matrix Subtraction
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