To simplify the problem imagine the half-life was 2.5 minutes. This means that there would be 10/2.5=4 periods of halving the mass, which means 1/2⁴=1/16 of 18g=1.125g.
So for the given half-life we calculate 10/2.552=3.9185 approx. So we now find 2 to this power=15.1211 approx and divide into 18=1.19g. This is close to the rough estimate we did earlier.
Answer:
x = 4
Step-by-step explanation:
5x-50=30-15x
5x +15x =30+50
20x= 80
Divide both sides of the equation by 20
x = 4
I hope it helps
<span>1)
11x+5y=20
2x+5y=-25
multiply the second equation by - 1 and add the result with the first equation:
11x + 5y = 20
- 2x - 5y = 25
-------------------
9x = 45
=> x = 45 / 9
=> x = 5
Replace in </span><span>2x+5y=-25
=> 2(5) + 5y = - 25
5y = - 25 - 10
5y = - 35
y = - 35 / 5
y = - 7
2)
3x+7y=-21
3x-7y=63</span>
Add the two equations:
3x + 3x + 0 = - 21 + 63
6x = 42
=> x = 42 / 6
=> x = 7
Replace in <span>3x-7y=63
3(7) - 7y = 63
=> 7y = 21 - 63
=-> 7y = - 42
=> y = - 42 / 6
=> y = - 7</span>
Answer:
Since Tracy is charged $29 for 250 free minutes so:
For x ≤ 250, f(x) = $29
tracy is charged an extra $0.35 per minute for calls over 250 minutes, so:
For x ≥ 250, f(x) = 29 + 0.35(x - 250)
Answer:
8x to the power of 7 y to the power of 6
Step-by-step explanation: