Answer:
5/15
Step-by-step explanation:
Answer:
x= 13/22
Step-by-step explanation:
you can substitute y= 34 x on the second equation
34x = -54x +52 add 54x to both sides
34x +54x = -54x +54x +52
88x = 52 divide both side by 4
22x = 13 divide both sides by 22
x= 13/22
Answer:
The half-life of the radioactive substance is 135.9 hours.
Step-by-step explanation:
The rate of decay is proportional to the amount of the substance present at time t
This means that the amount of the substance can be modeled by the following differential equation:

Which has the following solution:

In which Q(t) is the amount after t hours, Q(0) is the initial amount and r is the decay rate.
After 6 hours the mass had decreased by 3%.
This means that
. We use this to find r.







So

Determine the half-life of the radioactive substance.
This is t for which Q(t) = 0.5Q(0). So







The half-life of the radioactive substance is 135.9 hours.
Answer:
<u>135.94 feet</u>
Step-by-step explanation:
Split the problem into two parts :
- Distance between viewer and building
- Height of the top part of the building
<u>Distance between viewer and building</u>
- The lower part of the building is 40 feet, as it is mentioned the viewer is 40 feet above street level
- Let the distance be called 'd'
- Therefore, tan37° = 40/d
- tan37° = 3/4 = 0.75
- ⇒ 40/d = 0.75
- ⇒ d = 40/(3/4) = 40 x 4/3 = 160/3 = 53.3 feet
<u>Height of the top part of the building</u>
- Let the height of the top part be 'h'
- Therefore, tan61° = h/d = h/53.3
- tan61° = 1.8
- ⇒ h/53.3 = 1.8
- ⇒ h = 53.3 x 1.8 = 95.94 feet
<u>Total height of building</u>
- Lower part + Top part
- 40 + 95.94
- <u>135.94 feet</u>
<u />
There are 52 weeks a year
In 2 years there are 104 weeks
Total paid
35×104=3,640
markup rate
((3,640−2,400)÷2,400)×100=51.7%
It's b