Answer:
y= -20
Step-by-step explanation:
You can write this ratio in two other ways:
7 to 13
7 : 13
Answer: -5/6g -2h + 4/3j
Step-by-step explanation:
Distribute -1/3 over the 5/2g, 6h, and -4j, in other words, multiply -1/3 to those other numbers and you get the answer.
Answer:
155
Step-by-step explanation:
you add 72 and 83 together
Answer: 30g
Step-by-step explanation:
In this question (t½) of isotope is 40 days, which means that after 40 days half of the sample would have decayed and half would be left as it is.
After 40 days ( first half life) 240 /2 = 120 g decays and 120 g remains left.
After another 40 days ( two half lives or 80 days) 120 /2 = 60 g decays and 60 g remains left .
after three half lives or 120 days, 60/2 = 30g decay and 30 g of the isotope will be left.