the catch is that the top numbers are atomic masses the bottom numbers are the numbers of protons and electrons in an uncharged atom. they are the number of that atoms as you would find them on the periodic table. further, the numbers on the left are used to determine the missing numbers on the right
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