Create the following matrix H:
H=⎡⎣⎢1.251451.52401.7533521302.2522 52.53202.75415⎤⎦⎥
(a) Create a 2 x 5 matrix G such that its first row includes the first three elements
and the last two elements of the first row of H, and the second row
of G includes the last five elements of the third row of H.
(b) Create a 4 x 3 matrix K such that the first, second, third, and fourth rows
are the second, third, fifth and seventh columns of matrix H.

a) {[1.25  1.5  1.75  2.5  2.75]

    [35  30  25  20  15]  }

b) {[1.5  2  40]

    [1.75  3  35]

    [2.25  2  25]

    [2.75  4  15]}

Explanation:

Matrix H: {[1.25  1.5  1.75  2  2.25  2.5  2.75]

                [1  2  3  1  2  3  4]

                [45  40  35  30  25  20  15]}

Its always important to get the dimensions of your matrix right. "Roman Columns" is the mental heuristic I use since a matrix is defined by its rows first and then its column such that a 2 X 5 matrix has 2 rows and 5 columns.

Next, it helps in the beginning to think of a matrix as a grid, labeling your rows  with letters (A, B, C, ...) and your columns with numbers (1, 2, 3, ...).

For question a, we just want to take the elements A1, A2, A3, A6 and A7 from matrix H and make that the first row of matrix G. And then we will take the elements B3, B4, B5, B6 and B7 from matrix H as our second row in matrix G.

For question b, we will be taking columns from matrix H and making them rows in our matrix K. The second column of H looks like this:

{[1.5]

[2]

[40]}

Transposing this column will make our first row of K look like this:

{[1.5  2  40]}

Repeating for columns 3, 5 and 7 will give us the final matrix K as seen above.