Răspuns :
4xa+2xb=90
b=3xa
4xa+2x3xa=90
10xa=90
a=90:10
a=9lei paharul
b=3x9
b=27lei platoul
4x9+2x27=36+54=90 proba
b=3xa
4xa+2x3xa=90
10xa=90
a=90:10
a=9lei paharul
b=3x9
b=27lei platoul
4x9+2x27=36+54=90 proba