Question

What are the answers for number 6 & 7????

Answer 1

`\large\boxed{6.\ 2\left[\begin{array}{ccc}2&3\\1&5\end{array}\right] +\left[\begin{array}{ccc}1&2\\3&4\end{array}\right] =\left[\begin{array}{ccc}5&8\\5&14\end{array}\right] }\\\boxed{7.\ 3^2-4(-2+5)=-3}`

Explanation:

`6.\\2\left[\begin{array}{ccc}2&3\\1&5\end{array}\right] +\left[\begin{array}{ccc}1&2\\3&4\end{array}\right] =\left[\begin{array}{ccc}2\cdot2&2\cdot3\\2\cdot1&2\cdot5\end{array}\right] +\left[\begin{array}{ccc}1&2\\3&4\end{array}\right]\\\\=\left[\begin{array}{ccc}4&6\\2&10\end{array}\right] +\left[\begin{array}{ccc}1&2\\3&4\end{array}\right]=\left[\begin{array}{ccc}4+1&6+2\\2+3&10+4\end{array}\right] \\\\=\left[\begin{array}{ccc}5&8\\5&14\end{array}\right]`

`7.\\3^2-4(-2+5)\qquad\text{use PEMDAS}\\\\=9-4(3)\\\\=9-12\\\\=-3`