The table below shows the fossils found in various layers of an undisturbed rock:
fossils in rock layers
layer (from top) fossil in layer
1 a, c
2 e
3 a, d, f
4 b
5 f, c
6 d, b
which is most likely an index fossil?
a
b
d
e

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

the answer is: metamorphic rocks often show the presence of fossils, also a

hope i

-lavira: )