Question

Clasa A 5 exercitile sunt 4 dau coroana : 1)Rezolvati in multimea nr naturale inecuatia 2(x+3)<307-251 2)Rezolvati in multimea nr naturale inecuatica 2supra x+1<16 3)Suma a patru nr naturale consecutive este 90 Determinati nr 4) Adi rezolva zilnic cu 3 probleme mai mult decat in ziua precedenta.Stiind ca in 3 zile consecutive Adi a rezlvat 18 probleme, determinati cate probleme a rezolvat in prima zi.

Answer 1

1)2x+6<56
2x<50
x<25
x€{0,1,2,...,23,24}
2)/ e supra
2/(x+1)<16/1
(x+1)|2=>1.x+1=2=>x=1;2.x+1=1=>x=0
3)a+b+c+d=90
b=a+1
c=b+1=>c=a+2
d=c+1=>d=a+3
4a+6=90
4a=84
a=21
b=22
c=23
d=24
4)x+y+z=18
y=x+3
z=x+6
3x+9=18
x=9:3
x=3