Confusion related to matrix multiplication

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I am having this simple confusion.Lets consider a multivariate gaussian distribution with mean $\mu$ and precision matrix $K$. Then the exponential term is

$$(x-\mu)' K (x-\mu)$$

If I open the above expression, I will get $x'Kx- x'K\mu-\mu'Kx + \mu'K\mu$. The middle two terms are not equal, they were supposed to be same.

So I am wondering if I am doing something wrong. Any suggestions?

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The two "middle terms" are each other's transposes. Generally a matrix is not equal to its transpose. But notice that these are $1\times 1$ matrices, and every one of those is equal to its transpose.