Răspuns :
(78541-1514):77+3514-4504+y=77000:77+3514-4504+y=1000+3514-4504+y=4514-4504+y=10+y y=1524-10=1514
77000:77+3514-4504+y=1524____1000+3514-4504+y=1524____4514-4504+y=1524____10+y=1524____y=1524-10__y=1514