Answer:
0.67 cm/s
Step-by-step explanation:
The area of a square is given by :
....(1)
Where
x is the side of a square

Differentiating equation (1) wrt t.

When A = 81cm², the side of the square, x = 9 cm
Put all the values,

So, the length of the side of a square is changing at the rate of 0.67 cm/s.
Answer:
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Answer: $2936.27
Step-by-step explanation:
Present value = $1663
Rate = 5.5%
Time(n) = 19years
Future value= PV(1+r)^n
= 1663(1+5.5%)^19
= 1663(1.055)^19
=1663 × 2.766
=4599.86
Interest = Future value - Present value
= $4599 - $1663
= 2936