Answer:
I think 84 but you may need to check just to be sure :)
its B
Step-by-step explanation:
she went deeper than 21 feet so greater than 21
y = -1/2 x - 3.5
y = mx+ b
m is the slope of the line
m = -1/2
b is the y-intercept
b = -3.5
r = 57
Hope This Helps!
90 i think
