Point (x, y) is reflected across the y-axis. Which are the coordinates of its image? (-x, y) (-x, -y) (-y, -x) (x, -y)

The answer is -x,y since you flipping the point across the Y axis

Pax:
7.6 ft,   519 lb.
snowflake:
8.2 ft,   549 lb.
519 = 7.6 m + b
549 = 8.2 m + b

- 519 = - 7.6 m - b
+
  549 = 8.2 m + b

30 = 0.6 m
m = 30 : 0.6
m = 50
410 + b = 549
b = 549 - 410
b = 139
linear model:
y = 50 x + 139
jo jo:   5.8 ft,   460 lb.
y = 50 * 5.8 + 139 = 429
460 - 429 = 31 lb.
weight of dolphin jo jo differs most from the value predicted by the model.