Acertain element has a half life of 4.5 billion years. (a). you find a rock containing a mixture of the element and lead. you determine that 35% of the original element remains; the other 65% decayed into lead. how old is the rock? (b). analysis of another rock shows that it contains 55% of it's original element; the other 45% decayed into lead. how old is the rock.

Step-by-step explanation:

Given that a  certain element has a half life of 4.5 billion years.

For half life of 4.5 billion years we have the equation as

= where t is in billions of years.

When P(t) = 35% of original we have

After 6.816 billion years.

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b) Here

After 3.88 billion years.

f(x) has value 150 at x= 0

and 0 at x= 3

so d(f(x))/dt = slope = -150/3 = -50

0.6, 3/5, and 6% are the 3 same portion.

but, when they're all changed to a decimal they would equal to 0.6.

hope this , good luck!