Answer :

To find the distance between points [tex]\( P \)[/tex] and [tex]\( Q \)[/tex] with coordinates [tex]\( P = (3, 1) \)[/tex] and [tex]\( Q = (-3, -7) \)[/tex], we use the distance formula. The distance formula between two points [tex]\( (x_1, y_1) \)[/tex] and [tex]\( (x_2, y_2) \)[/tex] in a Cartesian plane is given by:

[tex]\[ d = \sqrt{(x_2 - x_1)^2 + (y_2 - y_1)^2} \][/tex]

For the given points [tex]\( P = (3, 1) \)[/tex] and [tex]\( Q = (-3, -7) \)[/tex]:
- [tex]\( x_1 = 3 \)[/tex]
- [tex]\( y_1 = 1 \)[/tex]
- [tex]\( x_2 = -3 \)[/tex]
- [tex]\( y_2 = -7 \)[/tex]

Substitute these values into the distance formula:

[tex]\[ d = \sqrt{((-3) - 3)^2 + ((-7) - 1)^2} \][/tex]

First, calculate the differences [tex]\( x_2 - x_1 \)[/tex] and [tex]\( y_2 - y_1 \)[/tex]:

[tex]\[ x_2 - x_1 = -3 - 3 = -6 \][/tex]
[tex]\[ y_2 - y_1 = -7 - 1 = -8 \][/tex]

Next, square these differences:

[tex]\[ (-6)^2 = 36 \][/tex]
[tex]\[ (-8)^2 = 64 \][/tex]

Now, add the squared differences:

[tex]\[ 36 + 64 = 100 \][/tex]

Finally, take the square root of the sum:

[tex]\[ d = \sqrt{100} = 10 \][/tex]

Therefore, the distance [tex]\( PQ \)[/tex] is:

[tex]\[ \boxed{10} \][/tex]