Im in 6th grade and don’t understand please help !

3R's :

reduce

reuse

recycle

the other living things produce can most of the time use the 3rs and our waste cannot some of the time

;

the volume increases

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