Răspuns :
notezi cu X caietele si cu Y pixurile
Y+4=X
15X+4Y=288
15(Y+4)+4Y=288
15Y+60+4Y=288
19Y+60=288
19Y=288-60
19Y=228
Y=228÷19
Y=12
si dupa inlocuiesti in
Y+4=X
12+4=X
X=16
Y+4=X
15X+4Y=288
15(Y+4)+4Y=288
15Y+60+4Y=288
19Y+60=288
19Y=288-60
19Y=228
Y=228÷19
Y=12
si dupa inlocuiesti in
Y+4=X
12+4=X
X=16
Notam cu:c - caiete
p-pixuri
c=p+4 lei
15c+4p=288
__________/____
1pix=?lei
1 caiet=?lei
__________//____
15c+4p=288
(p+4)×15+4p=288lei
15p+60+4p=288lei
19p+60=288lei
19p=288lei-60
19p=228lei
1p=12lei
1c=1p+4lei
1c=12lei+4lei
1c=16lei
R:1 caiet=16lei
1 pix=12lei
Sper ca te-am ajutat
p-pixuri
c=p+4 lei
15c+4p=288
__________/____
1pix=?lei
1 caiet=?lei
__________//____
15c+4p=288
(p+4)×15+4p=288lei
15p+60+4p=288lei
19p+60=288lei
19p=288lei-60
19p=228lei
1p=12lei
1c=1p+4lei
1c=12lei+4lei
1c=16lei
R:1 caiet=16lei
1 pix=12lei
Sper ca te-am ajutat