Element X is a radioactive isotope such that every 18 years, its mass decreases by half. Given that the initial mass of a sample of Element X is 500 grams, how long would it be until the mass of the sample reached 210 grams, to the nearest tenth of a year?

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value

there should be an link icon on the bottom of the text box you get. it looks like a paperclip!