Answer:
It takes 27 minutes for the element to decay to 35 grams
Step-by-step explanation:
Given:
Initial amount = 790 grams
Final amount = 35 grams
Half life = 6 minutes
To find:
Time taken for the element to reduce into 35 grams = ?
Solutions
Time taken = ![half life \times \frac{ log(\frac{ initial amount}{final amount})}{log(2)}](https://tex.z-dn.net/?f=half%20life%20%20%5Ctimes%20%5Cfrac%7B%20log%28%5Cfrac%7B%20initial%20amount%7D%7Bfinal%20amount%7D%29%7D%7Blog%282%29%7D)
On substituting the values given, Time taken
= ![6 \times \frac{log(\frac{790}{35})}{log(2)}](https://tex.z-dn.net/?f=6%20%5Ctimes%20%5Cfrac%7Blog%28%5Cfrac%7B790%7D%7B35%7D%29%7D%7Blog%282%29%7D)
= ![6 \times \frac{log(22.57)}{log(2)}](https://tex.z-dn.net/?f=6%20%5Ctimes%20%5Cfrac%7Blog%2822.57%29%7D%7Blog%282%29%7D)
= ![6 \times 4.496](https://tex.z-dn.net/?f=6%20%5Ctimes%204.496)
= 26.97
= 27 minutes
The answer is : B. (X-10)(x-4)
There’s no picture or anything so try again
4+2x = x (x = student in smaller group)
4 + 2x + x = 28 (total # of students)
4+ 3x = 28
3x = 24
x = 8
8 students in the smaller group
4 + 2(8) = 20 students in the larger group
Answer:
![p=18h](https://tex.z-dn.net/?f=p%3D18h)
or
![p=\dfrac{450}{30}\cdot 1.2\cdot h](https://tex.z-dn.net/?f=p%3D%5Cdfrac%7B450%7D%7B30%7D%5Ccdot%201.2%5Ccdot%20h)
Step-by-step explanation:
If Alexa worked 30 hours last week and earned $450, then her hourly payment is
![\dfrac{\$450}{30}=\$15.](https://tex.z-dn.net/?f=%5Cdfrac%7B%5C%24450%7D%7B30%7D%3D%5C%2415.)
Her payment has now been increased by 20%, so her hourly payment becomes
![\$15\cdot 1.2=\$18.](https://tex.z-dn.net/?f=%5C%2415%5Ccdot%201.2%3D%5C%2418.)
If she worked h hours, then she earned
If her new payment is p, then
![p=18h](https://tex.z-dn.net/?f=p%3D18h)
or
![p=\dfrac{450}{30}\cdot 1.2\cdot h.](https://tex.z-dn.net/?f=p%3D%5Cdfrac%7B450%7D%7B30%7D%5Ccdot%201.2%5Ccdot%20h.)