Question

Elevii unei clase se incoloneaza cate 4, 6 si 8 si raman mereu doi elevi neincolonati. Cati elevi sunt in clasa?

Answer 1

x:4=a rest 2
x:6=b rest 2
x:8=c rest 2
x=4a+2
x=6b+2
x=8c+2
notam x-2=y
y=4a=6b=8c=>y e cmmmc-ul lui 4,6,8
4=2²
6=2*3
8=2³
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[4,6,8]=2³*3=8*3=24=>y=24
x-2=24
x=26=> sunt 26 de elevi in clasa