J = 14
J = 1/2S + 4 1/2
14 = 1/2S + 9/2....multiply everything by 2 to get rid of fractions
28 = S + 9
28 - 9 = S
19 = S
check...
14 = 1/2S + 9/2......S = 19
14 = 1/2(19) + 9/2
14 = 9 1/2 + 9/2
14 = 19/2+ 9/2
14 = 28/2
14 = 14 (correct)
so the sister is 19 <===
Answer:
5.4 hr i think
Step-by-step explanation:
Answer:
Average velocity is 32 miles/hr.
Step-by-step explanation:
Given that a particle moves on a line away from its initial position so that after t hours it is
miles from its initial position.
We have to find the average velocity of the particle over the interval [1, 4].
As, average velocity is the change is position over the change in time.
![s(4)=6(4)^2+2(4)=104](https://tex.z-dn.net/?f=s%284%29%3D6%284%29%5E2%2B2%284%29%3D104)
![s(1)=6(1)^2+2(1)=8](https://tex.z-dn.net/?f=s%281%29%3D6%281%29%5E2%2B2%281%29%3D8)
∴ ![\text{Average Velocity=}\frac{s(4)-s(1)}{4-1}](https://tex.z-dn.net/?f=%5Ctext%7BAverage%20Velocity%3D%7D%5Cfrac%7Bs%284%29-s%281%29%7D%7B4-1%7D)
=![\frac{104-8}{3}=\frac{96}{3}=32miles/hr](https://tex.z-dn.net/?f=%5Cfrac%7B104-8%7D%7B3%7D%3D%5Cfrac%7B96%7D%7B3%7D%3D32miles%2Fhr)
Hence, average velocity is 32 miles/hr.