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The matrix XX in the equation AX=BAX = B, such that A=[1302]A = \begin{bmatrix} 1 & 3 \\ 0 & 2 \end{bmatrix} and B=[1−102]B = \begin{bmatrix} 1 & -1 \\ 0 & 2 \end{bmatrix} is given by

Solution

✅ Correct Option: 1

Given A=[1302]A = \begin{bmatrix} 1 & 3 \\ 0 & 2 \end{bmatrix} and B=[1−102]B = \begin{bmatrix} 1 & -1 \\ 0 & 2 \end{bmatrix}, we need to find matrix XX such that AX=BAX = B.

From AX=BAX = B:

X=A−1BX = A^{-1}B


For a 2×2 matrix [abcd]\begin{bmatrix} a & b \\ c & d \end{bmatrix}, the inverse is:

A−1=1ad−bc[d−b−ca]A^{-1} = \frac{1}{ad-bc}\begin{bmatrix} d & -b \\ -c & a \end{bmatrix}

For matrix AA where a=1,b=3,c=0,d=2a = 1, b = 3, c = 0, d = 2:

ad−bc=(1)(2)−(3)(0)ad - bc = (1)(2) - (3)(0)

=2= 2

Therefore:

A−1=12[2−301]A^{-1} = \frac{1}{2}\begin{bmatrix} 2 & -3 \\ 0 & 1 \end{bmatrix}


Now calculate X=A−1BX = A^{-1}B:

X=12[2−301][1−102]X = \frac{1}{2}\begin{bmatrix} 2 & -3 \\ 0 & 1 \end{bmatrix}\begin{bmatrix} 1 & -1 \\ 0 & 2 \end{bmatrix}

Position (1,1): 2(1)+(−3)(0)=22(1) + (-3)(0) = 2

Position (1,2): 2(−1)+(−3)(2)=−2−6=−82(-1) + (-3)(2) = -2 - 6 = -8

Position (2,1): 0(1)+1(0)=00(1) + 1(0) = 0

Position (2,2): 0(−1)+1(2)=20(-1) + 1(2) = 2


X=12[2−802]X = \frac{1}{2}\begin{bmatrix} 2 & -8 \\ 0 & 2 \end{bmatrix}

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