![\textsf{\large{\underline{Solution 5}:}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/pqovdb7ap6xw4s324olfcl0bpkxo2jwv07.png)
Here:
![\rm:\longmapsto A =\begin{bmatrix} 7&0\\ 3&5\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/72tdcq3y93j5rkuq9o1uf8wj7h18o1k4yu.png)
![\rm:\longmapsto B=\begin{bmatrix} 3&0\\ 0&4 \end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/tbzl5tofwal0tgaiti5ub3hfm4refz35k9.png)
Therefore, the matrix 3A - 4B will be:
![\rm = 3\begin{bmatrix} 7&0\\ 3&5\end{bmatrix} - 4\begin{bmatrix} 3&0 \\ 0&4\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/oz8sbt1zskab6iommzi13u9ivu1wrr9oxr.png)
![\rm = \begin{bmatrix} 21&0\\ 9&15\end{bmatrix} - \begin{bmatrix} 12&0 \\ 0&16\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/hzyibr19rhiano54rdsjvr5iskmn7k7jys.png)
![\rm = \begin{bmatrix} 9&0\\ 9& - 1\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/3bt3d06s7jsiuf0a0u2z6ridapr8upenwn.png)
Therefore:
![\rm: \longmapsto 3A - 4B = \begin{bmatrix} 9&0\\ 9& - 1\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/48gxon9vbex1z1snw7y0dbpsfa9gh7aadh.png)
![\textsf{\large{\underline{Learn More}:}}](https://img.qammunity.org/2022/formulas/mathematics/high-school/zjeck17jgvcnfvjl19gpm0hn28mbezg49p.png)
Matrix: A matrix is a rectangular arrangement of numbers in the form of horizontal and vertical lines.
Horizontal lines are called rows and vertical lines are called columns.
Order of Matrix: A matrix containing x rows and y column has order x × y and it has xy elements.
Different types of matrices:
Row Matrix: This type of matrices have only 1 row. Example:
![\rm:\longmapsto A=\begin{bmatrix}\rm 1&\rm 2&\rm 3\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/z3ihfnftrubpm93r2idsain27r6v1v3ihw.png)
Column Matrix: This type of matrices have only 1 column. Example:
![\rm:\longmapsto A=\begin{bmatrix}\rm1\\ \rm2\\ \rm3\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/b551il1nzio9cgxan3h3veyf3sjkn0aewv.png)
Square Matrix: In this type of matrix, number of rows and columns are equal. Example:
![\rm:\longmapsto A=\begin{bmatrix}\rm 1&\rm 2\\ \rm 3&\rm 4\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/xawqt25ywijxi69c1d6zamec9enj8vdrmj.png)
Zero Matrix: It is a matrix with all elements present is zero. Example:
![\rm:\longmapsto A=\begin{bmatrix}\rm 0&\rm 0\\ \rm 0&\rm 0\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/tmo528wwr9fy3uxyx9gp5qsc67b72pz9fb.png)
Identity Matrix: In this type of matrix, diagonal element is 1 and remaining elements are zero. An Identity matrix is always a square matrix. Example:
![\rm:\longmapsto A=\begin{bmatrix}\rm 1&\rm 0\\ \rm 0&\rm 1\end{bmatrix}](https://img.qammunity.org/2022/formulas/mathematics/high-school/z6uy17kjr7dscrjdfavnjeoa4vgrv8sqzh.png)