Y’all boi needs help g

c and d, are you supposed to check 3? or only 2?

with this one i know the answer in craters one reason i looked it up and i learned about it there is my evidence

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