Answer:
3960.4 bacteria
Step-by-step explanation:
The formula to solve the above question is given as:
P(t) = Po (2) ^t/k
P(t) = Population after time t = ?
Po = Initial population = 650 bacteria
t = Time in days = 7.3 days
k = doubling time = 2.8 days
P(t) = 650 × (2)^7.3/2.8
P(t) = 650 × 2^2.6071428571
P(t) = 650 × 6.0929582599
P(t) = 3960.4228689 bacteria.
Approximately = 3960.4 bacteria
Therefore, the number of bacteria the researcher will have after 7.3 days if they started with 650 bacteria is 3960.4 bacteria.
I think it’s 2. You can see this because if you count the squares in the smaller triangle it is 3 along. You would then need to double the amount of squares on all sides. This makes the larger triangle now 6 squares along. 6/3 is 2 making the scale factor 2. (This is only if I have read the question correctly and we are calculating small to big. If I have read it wrong and it is big to small it would be 1/2)

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9² = 12² + 15² - 2 (12) (15) cos (B)
81 = 144 + 225 - 360 cos(B)
81 = 369 - 360 cos (B)
360 cos (B) = 369 - 81
360 cos (B) = 288
cos (B) = 0.8
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Answer: Cosine B = 0.8
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12² = 15² + 9² - 2 (15)(9) cos (A)
144 = 225 + 81 - 270 Cos A
144 = 306 - 270 Cos A
270 Cos A = 162
Cos A = 3/5 or 0.6
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Answer: Cosine Angle A = 3/5