Step-by-step explanation:
for that we use Pythagoras, as the distance is always the baseline (Hypotenuse) of a right-angled triangle created by the x and y coordinate differences between the 2 points.
15.
distance² = (8-3)² + (9-2)² = 5² + 7² = 25 + 49 = 74
distance = sqrt(74) = 8.602325267...
16.
we need to write down the point coordinates first :
(-4, 3)
(1, -3)
distance² = (1 - -4)² + (-3 - 3)² = 5² + (-6)² = 25 + 36 = 61
distance = sqrt(61) = 7.810249676...