1)
(a + b + c + d + e) : 8 = 9 rest 3
a + b + c + d + e = 8 ×9 + 3
a + b+ c + d + e = 75
75 : 5 = 15 este al 3-lea nr.
15 - 1 = 14 al 2-lea nr.
15 - 2 = 13 primul nr.
15 + 1 = 16 al 4-lea nr.
15 + 2 = 17 al 5-lea nr.
numerele sunt; 13,14, 15, 16, 17
ver;(13+14+15+16+17)÷8=75÷8=9 rest 3
2)
a+(3×a-1)+(2×a+1)=299
a /---/
3a/---/---/---/-1
2a/---/---/+1
299+1=300
300:6=50(a)
3×50-1=149
50+50=100
ver; 50+149+100=299
3)
rate+gaste=120picioare; 120:2=60 capete
100-60=40capete purcei/ 40x4=160picioare
210-160=50/ 50:2=25 gaini
230-160=70/ 70:2=35 rate
25+35+40=100