Answer :

Let's solve the system of linear equations:

[tex]\[ \begin{cases} 7p - q = 2 \\ -21p + 3q = 5 \end{cases} \][/tex]

First, let's rewrite the equations for clarity:

1. [tex]\( 7p - q = 2 \)[/tex]
2. [tex]\( -21p + 3q = 5 \)[/tex]

Step 1: Eliminate one of the variables

We can start by eliminating [tex]\(q\)[/tex]. Let's manipulate the first equation so that the coefficients of [tex]\(q\)[/tex] match in both equations.

Multiply the first equation by 3:

[tex]\[ 3(7p - q) = 3 \cdot 2 \][/tex]

This gives us:

[tex]\[ 21p - 3q = 6 \][/tex]

Now the system is:

[tex]\[ \begin{cases} 21p - 3q = 6 \\ -21p + 3q = 5 \end{cases} \][/tex]

Step 2: Add the equations

[tex]\[ (21p - 3q) + (-21p + 3q) = 6 + 5 \][/tex]

Simplifying this:

[tex]\[ 0 = 11 \][/tex]

This equation is a contradiction, which means that there is no solution to this system of equations. The equations are inconsistent.

Therefore, the system of equations:

[tex]\[ \begin{cases} 7p - q = 2 \\ -21p + 3q = 5 \end{cases} \][/tex]

has no solution.