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If A=[2443],X=[n1],B=[811]\mathrm{A}=\left[\begin{array}{ll}2 & 4 \\ 4 & 3\end{array}\right], \mathrm{X}=\left[\begin{array}{l}\mathrm{n} \\ 1\end{array}\right], \mathrm{B}=\left[\begin{array}{c}8 \\ 11\end{array}\right] and AX=BA X=B, then the value of nn will be :

Solution

✅ Correct Option: 3

A=[2443],X=[n1],B=[811]A = \left[\begin{array}{ll}2 & 4 \\ 4 & 3\end{array}\right], X = \left[\begin{array}{l}n \\ 1\end{array}\right], B = \left[\begin{array}{c}8 \\ 11\end{array}\right]

The equation is:

AX=BAX = B

Expanding this:

[2443][n1]=[811]\left[\begin{array}{ll}2 & 4 \\ 4 & 3\end{array}\right] \left[\begin{array}{l}n \\ 1\end{array}\right] = \left[\begin{array}{c}8 \\ 11\end{array}\right]

Performing the matrix multiplication:

[2n+44n+3]=[811]\left[\begin{array}{c}2n + 4 \\ 4n + 3\end{array}\right] = \left[\begin{array}{c}8 \\ 11\end{array}\right]

This gives us two equations:

2n+4=82n + 4 = 8

4n+3=114n + 3 = 11

From the first equation:

2n=42n = 4

n=2n = 2

Let's verify with the second equation:

4(2)+3=8+3=114(2) + 3 = 8 + 3 = 11

The value of n is 2.

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