Question

B+b=9 si B-b=3
B=? b=?

Answer 1

Daca aduni ambele relatii obtii ca

B+b+B-b=9+3

2B=12

B=12/2

B=6

B+b=9

b=9-B

b=9-6

b=3

Answer 2

B+b=9

B-b=3

B=b+3

b+3+b=9

2b+3=9

2b=6

b=3

B=3+3

B=6