Element X is used to date fossils, and has a half life of 400 years. If a fossil with Element X in is found to be 1200 years old, how many half lives have gone by?

what about chemical X?

Step-by-step explanation:

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

michael scott & dwight schrute

step-by-step explanation:

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