Răspuns :
(b+3127)-2789=5146=>(b+3127)=5146+2789=>b+3127=8935=>b=8935-3127 b=5808
v:(5808+3127)-2789=8935-2789=5146
(b+3127)- 2789 =5146
b+3127=5146+2789
b+3127= 7935
b=7935- 3127
b=4808
b+3127=5146+2789
b+3127= 7935
b=7935- 3127
b=4808