Answer :

To solve the system of linear equations:
[tex]\[ \begin{cases} 7p - q = 2 \\ -21p + 3q = 5 \end{cases} \][/tex]
we can use the method of substitution or the method of elimination. Here, let's use the method of elimination to find the values of [tex]\( p \)[/tex] and [tex]\( q \)[/tex].

### Step 1: Align the system of equations:
[tex]\[ \begin{array}{c} 7p - q = 2 \\ -21p + 3q = 5 \end{array} \][/tex]

### Step 2: Let's multiply the first equation by a constant such that the coefficient of [tex]\( p \)[/tex] in both equations is the same. We choose to multiply the first equation by 3:
[tex]\[ 3 \cdot (7p - q) = 3 \cdot 2 \\ 21p - 3q = 6 \][/tex]

So the system now looks like:
[tex]\[ \begin{cases} 21p - 3q = 6 \\ -21p + 3q = 5 \end{cases} \][/tex]

### Step 3: Add the two equations to eliminate [tex]\( q \)[/tex]:
[tex]\[ (21p - 3q) + (-21p + 3q) = 6 + 5 \\ 0 = 11 \][/tex]

### Step 4: Since adding these equations gave us the result [tex]\( 0 = 11 \)[/tex], which is a contradiction, this means that there is no solution to the system of equations. The system is inconsistent.

Therefore, there are no values of [tex]\( p \)[/tex] and [tex]\( q \)[/tex] that satisfy both equations simultaneously.