Question

I didn't really understand the explanation, can it be broken down

Answer 1

yes it can be broken down

Answer 2

40.06

Step-by-step explanation:

(23 * 39) + (48 * 40) + (29 * 41)

100

= 40.06

formula:

(% of isotope A * mass of A) + (% of isotope B * mass of B) ......

100