Răspuns :
a-105+300+30=700
a-105+300=700-30=670
a-105=670-300=370
a=105+370
a=475
475-105+300+30=370+300+30=700
a-105+300=700-30=670
a-105=670-300=370
a=105+370
a=475
475-105+300+30=370+300+30=700