Hj and ik are opposite sides of the rectangle so they areequal in length.
19 + 2x = 3x + 22
19-22 = 3x-2x
x = -3
We can't find the length of the diagonals as we have no information about the width.
Answer:
(a) 100 fishes
(b) t = 10: 483 fishes
t = 20: 999 fishes
t = 30: 1168 fishes
(c)

Step-by-step explanation:
Given


Solving (a): Fishes at t = 0
This gives:






Solving (a): Fishes at t = 10, 20, 30






Solving (c): 
In (b) above.
Notice that as t increases from 10 to 20 to 30, the values of
decreases
This implies that:

So:
The value of P(t) for large values is:




12 is the answer because when you add the green and blue you get 5 and 5×4= 20 so you multiply the blue by 4 and the green by 4 and add them together which = 20. so 3×4=12 and 2×4=8 so your answer is again 12