Răspuns:
7.
3 tract..........8 zile
4 tract.............x
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x=3×8:4=6 zile
3 tract..........8 zile
x.................2 zile
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x=3×8:2=12tractoare
8.
{[(a-1,985):0,3-0,35]×0,9+6,27}:3=50
[(a-1,985):0,3-0,35]×0,9+6,27=50×3
[(a-1,985):0,3-0,35]×0,9=150-6,27
(a-1,985):0,3-0,35=143,73:0,9
(a-1,985):0,3=159,7+0,35
a-1,985=160,05×0,3
a=48,015+1,985
a=50
10.
p+g=35=>p=35-g
4p+2g=82
4(35-g)+2g=82
140-4g+2g=82
2g=140-82
g=58:2=>g=29 gaini
p=35-29=>p=6 porci