Răspuns :
Răspuns:
a+b=40=>a=40-b
5a-2b=137
5(40-b)-2b=137
200-5b-2b=137
7b=200-137
b=63:7=>b=9 raspunsuri gresite
a=40-9=>a=31 raspunsuri bune
a+b=40
a=40-b
5a-2b=137
5×(40-b)-2b=137
200-7b=137
7b=63
b=9
a=31 (răspunsuri corecte)
Răspuns:
a+b=40=>a=40-b
5a-2b=137
5(40-b)-2b=137
200-5b-2b=137
7b=200-137
b=63:7=>b=9 raspunsuri gresite
a=40-9=>a=31 raspunsuri bune
a+b=40
a=40-b
5a-2b=137
5×(40-b)-2b=137
200-7b=137
7b=63
b=9
a=31 (răspunsuri corecte)