Question

I Need help with matrices!!! Will fan and metal!!!

Answer 1

Hmmmm, It's 420

Answer 2

What is the solution of the matrix equation?
[9 4]X= [-9 -6]
2 1 -1 -8

Answer 3

@zepdrix

Answer 4

@DatChinookGuy

Answer 5

The quickest way would probably be to compute the inverse of \(\begin{bmatrix}9&4\\2&1\end{bmatrix}\), then multiply both sides by it.
\[\begin{bmatrix}9&4\\2&1\end{bmatrix}^{-1}=\frac{1}{\begin{vmatrix}9&4\\2&1\end{vmatrix}}\begin{bmatrix}1&-4\\-2&9\end{bmatrix}=\frac{1}{9-8}\begin{bmatrix}1&-4\\-2&9\end{bmatrix}=\begin{bmatrix}1&-4\\-2&9\end{bmatrix}\]
Now,
\[\begin{bmatrix}1&-4\\-2&9\end{bmatrix}\begin{bmatrix}9&4\\2&1\end{bmatrix}X=X=\begin{bmatrix}1&-4\\-2&9\end{bmatrix}\begin{bmatrix}-9&-6\\-1&-8\end{bmatrix}=\cdots \]