Question

intr-o zi 15 fete si 10 baieti din grupul micii ecologisti au plantat 420 panselute a 2 zi 12 fete si 10 baieti au plantat 360 de panselute Cate panselute a plantat un baiat si cate o fata pe zi?

Answer 1

aflam cate panselute a plantat o fata in primazi420; 15=28panselute                   apoi un bait in primazi 420;10=42pas 
apoi adoua zi o fata 360;12=30
un baiat a doua zi 360;10=36
28+12=40pans o fata 
42+36=78pans un baiat

Answer 2

15 f + 10 b = 420 panselute
12 f + 10 b = 360 panselute

Rezolvare:
420 - 360 = 60 panselute
60 : 3 = 20 panselute ( 1 fata)

420 - 20 x 15 = 420 - 300 = 120
120 : 10 = 12 panselute ( 1 baiat)

Verificare:
15 x 20 + 10 × 12 = 300 + 120 = 420 panselute
12 × 20 + 10 x 12 = 240 + 120 = 360 panselute