a+b=3971 a-b=7 a=? b=?

Răspuns :

a+b=3971

a-b=7 =>a=7+b

inlocuim

7+b+b=3971

7+2b=3971

2b=3971-7

2b=3964

b=1982

a+1982=3971

a=1989

a-b=7=>a=b+7
b+7+b=3971
2b=3964
b=3964:2
b=1982=>
a=1982+7=1989