ten tens are one hundred and then they both have 4 tens or forty
Answer:
a) -3/13
b) -1/8
Step-by-step explanation:
a) - (21 / 7) / (91 / 7) = 3/13
b) (32 / 32 ) / - (256 / 32) = -1/8
-5║4y-11║-3=12
-5║4y-11║-3 +3=12+3
- 5║4y-11║=15
-5/5║4y-11║=15/-5
║4y-11║=-3
4y-11=-3 -5║4y-11║-3=12
4y-11+11=-3+11 -5║4(2)-11║-3=12
4y=8 -5║-3║-3=12
4y/4=8/4 -5 (3)-3=12
y=2 -18≠12
4y-11=3 -5║4y-11║-3=12
4y-11+11=3+11 -5║4(7/2)-11║-3=12
4y=14 -5(3)-3=12
4y/4=14/4 -18≠ 12
y=7/2
No solutions
The mass of substance left after 7 days is 13.09 g
The mass of substance left, N is given by
N = N₀exp(-λt) where λ = decay constant and N₀ = initial mass of substance present = 24 g and t = time
Also, λ = 0.693/t' where t' = half-life of iodine = 8 days
So, λ = 0.693/t'
λ = 0.693/8
λ = 0.086625/day
Since the mass of substance left is N = N₀exp(-λt) and we require the mass of substance after t = 7 days,
N = N₀exp(-λt)
N = 24 gexp(-0.086625/day × 7 days)
N = 24 gexp(-0.606375)
N = 24 g × 0.5453
N = 13.09 g
So, the mass of substance left after 7 days is 13.09 g
Learn more about radioactive decay here:
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