Question

Given the matrices A and B shown below, find –3B+ } A.251 =[25OB =0

Answer 1

Given 2 matrices A and B

`A=\begin{bmatrix}{25} & {25} & {} \\ {0} & {-5} & {} \\ & {} & \end{bmatrix}\text{ and B=}\begin{bmatrix}{8} & {3} & \\ {3} & {0} & \\ & {} & {}\end{bmatrix}`

To find -3B+1/5A,

`\begin{gathered} -3B+(1)/(5)A=-3\begin{bmatrix}{8} & {3} & \\ {3} & {0} & {} \\ {} & {} & \end{bmatrix}+(1)/(5)\begin{bmatrix}{25} & {25} & {} \\ {0} & {-5} & {} \\ & {} & \end{bmatrix} \\ =\begin{bmatrix}{-24} & {-9} & \\ {-9} & {0} & {} \\ {} & {} & \end{bmatrix}+\begin{bmatrix}{(25)/(5)} & {(25)/(5)} & {} \\ {0} & {-(5)/(5)} & {} \\ & {} & \end{bmatrix} \\ =\begin{bmatrix}{-19} & {-4} & \\ {-9} & {-1} & {} \\ & {} & {}\end{bmatrix} \end{gathered}`