Question

(a:6)+25=31
(72:a)+48=56

Answer 1

(a:6)+25=31 a:6=31-25 a=6×6 a=36 (72:a)+48=56 72:a=56-48 a=72:8 a=9

Answer 2

(a:6)+25=31
rezolvăm ecuaţia de la coadă la cap cu sens contrar:
(a:6)=31-25=6
a=6·6=36
a⇒36
Probă:
(36:6)+25=6+25⇒31

(72:a)+48=56
(72:a)=56-48=8
a=72:8=9
a⇒9
Probă:
(72:9)+48=8+48⇒56