51cm / 3 X 5 = 85cm
Jijdididjdidjdjdjd

Look for an integrating factor
:

Multiply both sides by
:

Condense the left side as the derivative of a product:
![\dfrac{\mathrm d}{\mathrm dt}\left[(t+1)^{-7/9}y\right]=\dfrac{14}9t(t+1)^{-16/9}](https://tex.z-dn.net/?f=%5Cdfrac%7B%5Cmathrm%20d%7D%7B%5Cmathrm%20dt%7D%5Cleft%5B%28t%2B1%29%5E%7B-7%2F9%7Dy%5Cright%5D%3D%5Cdfrac%7B14%7D9t%28t%2B1%29%5E%7B-16%2F9%7D)
Integrate both sides:

For the integral on the right, substitute






Given that
, we get


For number 3, C is the answer.
#4. D
the coefficient of x² is negative, so the graph opens downward.
the two zeros are (3,0) and (5,0)
cannot see the question when editing. I'll post it in the comments.
Multiply 119 by 40 to get 4760 people who have a pool.
Answer:
Step-by-step explanation:
surface area=6*2.2²=6×4.84=29.04 m²