x-intrega suprafata de teren
legume: x-30x/100=x-3x/10=(10x-3x)/10=7x/10
griu: 7x/10-(7x/10)·20/100=7x/10-7x/50=(35x-7x)/50=28x/50=14x/25
porumb: 14x/25-(14x/25)·25/100=14x/25-7x/50=(28x-7x)/50=21x/50
21x/50=735
x=(735·50)/21
x=1750 ha intreaga suprafata
legume: 1750·30/100=525 ha
grau: (1750-525)·20/100=245 ha
porumb: (1750-525-245)·25/100=245 ha
floarea soarelui: 735 ha
525ha+245ha+245ha+735ha=1750 ha