The half-life for such a substance is the time 
required to have the amount (in grams 
) at time (in seconds 
), 
, decay to half the starting amount 
. In other words, for krypton-91, after 10 seconds we would have 
. We can use this information to solve for 
, then plug in various values of to find the amount of krypton-91 that's left...
But we don't need to! We already know it takes 10 seconds for half of the substance to decay. So if we start with 16 grams, then after 10 seconds, 8 grams will remain.
10s later (after a total of 20 seconds), 4g will remain.
10s later (30s), 2g will remain.
10s later (40s), 1g will remain.
10s later (50s), 1/2 g will remain.
Answer:
7,1/7
Step-by-step explanation:
2/3x=10
x=10÷2/3
x=10×3/2
x=5×3
x=15
Hi, the answer to this would be x6/9. I'm assuming the x4/3 and x2/3 are fractions and the x's aren't exponents. Now how I got x6/9 is shown here.
1st Step: Started off by regrouping the terms
1/3x3 x^4x^2
2nd Step: we can easily simplify 3x3 to just 9. And now we're left with 1/9x^4x^2
3rd Step: Now we can simplify the 1/9 to just x^4x^2/9
4th Step: Now we can use the product rule which is simple. So We add the exponents and simplify it to just one exponent. So x4+2=6 that simplifies to just x^6.
Final Answer: x^6/9.
Hope this helped you :)
