Question

Rezolvati in multimea numerelor naturale ecuatia: 3x(2x+1)-1=32.
Rezovati in multimea numerelor naturale inecuatia: 5x+ 1 mai mic sau egal 26.
Calculati: [(110+11x5)x3-22x7]:31.
Costin parcurge in prima zi 106 km, in a doua zi parcurge 29 km mai putin decat in prima zi, iar in a treia zi parcurge cat in primele doua zile la un loc. Calcuati distanta parcursa de Costin in cele trei zile. P.S. Nu cu segmente!!!

Answer 1

[(110+55)x3-22x7]:31=
=( 165x3-22x7):31=
=(495-154):31=
=341:31=
=11

cat parcurge in a doua zi ?
106-29=77
cat parcurge in a treia zi ?
106+77=183
cat parcurge in trei zile ?
106+77+183=366
  

3*(2x+1)-1=32
3*(2x+1)=33
2x+1=11
2x=10
x=10:2
x=5

Answer 2

5x+1mai mic sau egal26
5xmai mic sau egal26-1
xmai mic sau egal25:5
xmai mic sau egal5
3*(2x+1)-1=32
3*(2x+1)=32+1=33
2x+1=33:3
2x+1=11
2x=11-1
2x=10
x=10;2
x=5
xapartine{5}