Answer:
1. The day she was born, she weight 51.6 grams, because W(0) = 51.6.
2. She will weigh 140 grams after 17 days.
Explanation:
Linear function:
The weight of the chick after n days is given by a function in the following format:
W(n) = W(0) + an
In which W(0) is her weight on the first day and a is how much her weight increases by day.
She grows steadily at the rate of 5.2 grams per day.
This means that a = 5.2.
So
W(n) = W(0) + 5.2n
After 9 days, she weighs 98.4 grams.
This means that W(9) = 98.4, that is, when n = 9, W(n) = 98.4. So
98.4 = W(0) + 5.2*9
W(0) = 98.4 - 5.2*9
W(0) = 98.4 - 46.8
W(0) = 51.6
So
W(n) = 51.6 + 5.2n
1.
The day she was born, she weight 51.6 grams, because W(0) = 51.6.
2.
This is n for which W(n) = 140. So
W(n) = 51.6 + 5.2n
W(n) = 140
51.6 + 5.2n = 140
5.2n = 140 - 51.6
5.2n = 88.4
n = 88.4/5.2
n = 17
She will weigh 140 grams after 17 days.