If 14 g of a radioactive substance are present initially and 7 yr later only 7 g remain, how much of the substance will be present after 17 yr?

2.60 gr

Step-by-step explanation:

We need to consider the function where Po is the initial substance k is the rate of decay and t is the time

We know that and at the 7 th year P(t) is 7

This means

We solve for k

-50/3 is the final answer! : )

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.