Solving Matrices Question: Evaluate AB

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To evaluate AB, you need to multiply matrix A by matrix B. The notation "AB" indicates matrix multiplication. The user is seeking clarification on the term "evaluate," which in this context means to perform the multiplication operation. The response confirms that "evaluate AB" indeed refers to multiplying the two matrices. Understanding this notation is essential for solving matrix-related problems.
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hi there,

my teacher gave me the following question: 1. Evaluate AB

A= (19 81)
(2 10)

B= (9 -6)
(6 -7)

The book i have tells me how to add multiply and subtract matrices, i don't understand what evaluate AB means, is it multiply>?

Kind regards

lakitu
 
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"Evaluate AB" means "Multiply A by B".
 
Whenever two letters are together like that it always means to multiply. AB = A \times B
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks
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