1.
I zi - x/3 =>rest 2x/3
II zi - 1/4 · 2x/3 = x/6
III zi - 30 km
x/3 + x/6 + 30 = x
2x+x+180=6x
2x=180 =>x=90 km
2.
ceapa - 2/5 · 40000 = 16000 lei =>24000 lei pentru cartofi
3.
3/5 · 220 = 3·44 = 132 pagini in prima zi =>220-132=88 pagini a doua zi
4.
x+y=280
x=2y/5
2y/5 + y = 280
2y+5y=1400
7y=1400 =>y=200 =>x=80