Hey yall marry halloween but me solve this one question i have 2 leave hury

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

pop pop pop on a opp

a. a primary source combines several different accounts of an event. b. a primary source generally benefits from having been written after an event.

explanation: