What is the sum of the first 8 terms of the geometric series:
3+6+12+24+
0765
382
286
440

765.

Step-by-step explanation:

Sum of n terms = a1 (r^n - 1) / (r - 1) where a1 = the first term and r = the common ratio.

Here r = 6/3 = 2 and  a1 = 3.

Sum of 8 terms = 3 * ( 2^8 - 1) / 2 -1)

= 3 * 255

= 765 (answer).

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons