Question

Find A + B and 3A using the matrices

Answer 1

Explanation:

`A=\left[\begin{array}{ccc}2&-3\\0&5\\7&-2\end{array}\right] ,\ B=\left[\begin{array}{ccc}1&0\\10&-(1)/(2)\\3&1\end{array}\right] \\\\A+B=\left[\begin{array}{ccc}2&-3\\0&5\\7&-2\end{array}\right]+\left[\begin{array}{ccc}1&0\\10&-(1)/(2)\\3&1\end{array}\right]\\\\A+B =\left[\begin{array}{ccc}2+1&-3+0\\0+10&5+\left(-(1)/(2)\right)\\7+3&-2+1\end{array}\right] \\\\A+B=\left[\begin{array}{ccc}3&-3\\10&4(1)/(2)\\10&-1\end{array}\right]`

`3A=3\cdot\left[\begin{array}{ccc}2&-3\\0&5\\7&-2\end{array}\right]\\\\3A=\left[\begin{array}{ccc}3\cdot2&3\cdot(-3)\\3\cdot0&3\cdot5\\3\cdot7&3\cdot(-2)\end{array}\right]\\\\3A=\left[\begin{array}{ccc}6&-9\\0&15\\21&-6\end{array}\right]`