a)Presupunem ca toate ap.au 4 camere.⇒45*4=180 camere;180-140=40 camere;4-2=2(diferenta pe unitate);40:2=20 ap.cu 2 camere;45-20=25 ap.cu 4 camere.:Proba:20*2+25*4=40+100=140.
b)a = ap.cu 2 camere;
b = ap.cu 4 camere
a+b=45⇒a=45-b
2a+4b=140
2(45-b)+4b=140
90-2b+4b=140;2b=140-90
2b=50;b=50:2;b=25 ap.cu 4 camere.
a=45-25=20ap. cu 2 camere