Question

b) 4 este inclus in (2x+1; 3x+1; 5x-6);

Answer 1

Răspuns:

4=3x+1

4-1=3x

3x=3

x=3:3=>x=1

2×1+1=3 ; 3×1+1=4 ; 5×1-6=-1 ∉N

M={3;4;-1}

4=2x+1

4-1=2x

3x=2=>x=2/3

x=3/2∉N

4=5x-6

4+6=5x

x=10:5=>x=2∈N

2×2+1=5 ; 3×2+1=7 ; 5×2-6=4

M={5,7,4}

4 ⊂ (2x+1; 3x+1; 5x-6)