Final answer:
The distance between the points (3, -1) and (-9, 8) on the coordinate plane is 15 units.
Step-by-step explanation:
To find the distance between two points on the coordinate plane, you can use the distance formula:
d = √((x2 - x1)^2 + (y2 - y1)^2)
Substituting the given points (3, -1) and (-9, 8) into the formula, we have:
d = √((-9 - 3)^2 + (8 - (-1))^2) = √((-12)^2 + (9)^2) = √(144 + 81) = √225 = 15
So, the distance between the points is 15 units. Therefore, none of the given options (a) 13 units, (b) 11 units, (c) 10 units, (d) 12 units are correct.