A chemist begins studying a radioactive sample that has a mass of 450 grams.
sample decays at a rate of 6.7% each week. How much of the sample is left in
weeks? Round your answer to 2 decimal places.
A)287.74
B)301.19
C)332.06
D)318.14

The question should say How much of the sample is left inFIVEweeks? At least that is what I think you want to know.

The answer is 318.13 grams.

Step-by-step explanation:

450 - 6.7% = 419.85 grams End of week 1

419.85 - 6.7% = 391.72 grams End of week 2

391.72 - 6.7% = 365.47 grams End of week 3

365.47 - 6.7% = 340.98 grams End of week 4

340.98 - 6.7% = 318.13 grams End of week 5

simplifying

5(x + -6) = 2(x + 3)

reorder the terms:

5(-6 + x) = 2(x + 3)

(-6 * 5 + x * 5) = 2(x + 3)

(-30 + 5x) = 2(x + 3)

reorder the terms:

-30 + 5x = 2(3 + x)

-30 + 5x = (3 * 2 + x * 2)

-30 + 5x = (6 + 2x)

solving

-30 + 5x = 6 + 2x

solving for variable 'x'.

move all terms containing x to the left, all other terms to the right.

add '-2x' to each side of the equation.

-30 + 5x + -2x = 6 + 2x + -2x

combine like terms: 5x + -2x = 3x

-30 + 3x = 6 + 2x + -2x

combine like terms: 2x + -2x = 0

-30 + 3x = 6 + 0

-30 + 3x = 6

add '30' to each side of the equation.

-30 + 30 + 3x = 6 + 30

combine like terms: -30 + 30 = 0

0 + 3x = 6 + 30

3x = 6 + 30

combine like terms: 6 + 30 = 36

3x = 36

divide each side by '3'.

x = 12

simplifying

x = 12

this should .

correct answer is c. just did it

step-by-step explanation: