Answer:
Every week, the radioactivity decreases by a factor of 5
After 1 week, it goes from 5,000 to 1,000
2 weeks 1,000 / 5 =200
3 weeks 200 / 5 = 40
4 weeks 40 / 5 = 8
5 weeks 8 / 5 = 1.6
6 weeks 1.6 / 5 = 0.064
7 weeks 0.064 / 5 = 0.0128
8 weeks .0128 / 5 = 0.00256
9 weeks 0.00256 / 5 = 0.000512
10 weeks 0.000512 / 5 = 0.0001024
Step-by-step explanation:
B. 2 …………………………,.,,,,,.,.,.,.,.,,,.,
Answer:
B. 13
Step-by-step explanation:
Solve this by setting up system of equations:
0.25x + 0.10y = 3.95
x + y = 20
x equals the number of quarters and y equals the number of dimes. 0.25 is the value of a quarter and 0.10 is the value of a dime.
1. Multiply one equation to have the same coefficient as the other
0.10 · (x + y = 20) = 0.10x + 0.10y = 2
2. Subtract to find the value of one variable
0.25x + 0.10y = 3.95
<u>- 0.10x + 0.10y = 2</u>
0.15x = 1.95
3. Solve for x by dividing both sides by 0.15
x = 13
The answer is 90 because 360/4 (since it is a quadrilateral) is 90 degrees
