Answer:
It produced 3797.5 tons before.
22.5% of 4900 is 1102.5
That subtracted from 4900 is 3797.5 tons
The "k" value should have units and should be negative.
k = -.07 / seconds
Half-Life = ln (.5) / k
Half-Life = ln (.5) / -.07
Half-Life = -.693147 / -.07
Half-Life = 9.9 seconds
(actually, wkpedia says half-life of Krypton 91 is 8.57 seconds)
elapsed time = half-life * log (bgng amt / end amt) / log (2)
elapsed time = 9.9 * log (100 / 10) / 0.30102999566
elapsed time = 9.9 * 1 / 0.30102999566
<span><span>elapsed time = 9.9 * 3.3219280949
</span>
</span><span><span><span>elapsed time = 32.8870881395
</span>
</span>
</span>
<span>elapsed time = 32.89 seconds (rounded)
Source:
http://www.1728.org/halflife.htm
</span>
-(3x-2)=-4(x+1)-4
-3x+2=-4x-4-4
-3x+4x=-4-4-2
x=-10
Answer: perm will cost $48
Step-by-step explanation:
Let x be cost of haircut
So perm will cost her 2x
So
x + 2x + 5 = 77
3x = 72
x = 24
Perm will cost 2x24 = 48
Answer:
14 1/30
Step-by-step explanation:
convert the fractions so that the LCF is the denominator
1/5---->6/30
5/6----->25/30
5 6/30+8 25/30
13 31/30
14 1/30
