Answer :

Let's solve the problem step-by-step.

We are given the system of equations:
[tex]\[ 4m + 6n = 54 \][/tex]
[tex]\[ 3m + 2n = 28 \][/tex]

To find the determinant [tex]\( D \)[/tex] of the system, we set up the determinant of the coefficient matrix:

[tex]\[ D = \left| \begin{array}{cc} 4 & 6 \\ 3 & 2 \end{array} \right| \][/tex]

We calculate the determinant of a 2x2 matrix [tex]\( \left| \begin{array}{cc} a & b \\ c & d \end{array} \right| \)[/tex] using the formula:

[tex]\[ D = ad - bc \][/tex]

Here, [tex]\( a = 4 \)[/tex], [tex]\( b = 6 \)[/tex], [tex]\( c = 3 \)[/tex], and [tex]\( d = 2 \)[/tex].

Substituting these values into the formula, we get:

[tex]\[ D = (4 \times 2) - (6 \times 3) \][/tex]

Simplifying the expression step-by-step:

[tex]\[ D = 8 - 18 \][/tex]

[tex]\[ D = -10 \][/tex]

Therefore, the determinant [tex]\( D \)[/tex] is:

[tex]\[ D = -10 \][/tex]