Răspuns :
b+321-173+23=547
b+148+23=547
b+171=547
b=547-171
b=376
Probă :
376+321-173+23=697-173+23=524+23=547 (adevarat )
b+148+23=547
b+171=547
b=547-171
b=376
Probă :
376+321-173+23=697-173+23=524+23=547 (adevarat )