Răspuns :
a - prima clasa
b - a doua clasa
c - a treia clasa
x - nr de elevi care lipseste in acea zi
a+b+c=74
a-x=23
b-x=21
c-x=24
(aflam x)
23+21+24=68
=> 74-68=6 deci x=6:3=2
si atunci
a=23+2=25elevi
b=21+2=23elevi
c=24+2=26elevi
a - prima clasa
b - a doua clasa
c - a treia clasa
x - nr de elevi care lipseste in acea zi
a+b+c=74
a-x=23
b-x=21
c-x=24
(aflam x)
23+21+24=68
=> 74-68=6 deci x=6:3=2
si atunci
a=23+2=25elevi
b=21+2=23elevi
c=24+2=26elevi