Question

(2x+1)×y=42..........

Answer 1

42=1x42=2x24=3x14=6x7=7x6=14x3=21x2=42x1
2x+1=1, x=0, y=42
2x+1=2, x=1/2∉N
2x+1=3, x=1, y=14
2x+1=6, x=5/2∉N
2x+1=7, x=3, y=6
2x+1=14, x=13/2∉N
2x+1=21, x=10, y=2
2x+1=42, x=41/2∉N

Answer 2

42=1x42=2x21=3x14=6x7
aici se formeaza perechi de (x,y) astfel
1x42
2x+1=1 ;x=0⇒y=42 prima pereche (0;42)
2x+1=42;x=41/2 ⇒y=1 pereche (41/2;1)
2x21
2x+1=2;x=1/2  ⇒y=21 pereche (1/2;21)
2x+1=21;x=10⇒y=2 perechea (10;2)
3x14
2x+1=3⇒x=1 si y=14 perechea(1;14)
2x+1=14⇒x=13/2 si y=3 perechea (13/2;3)
6x7
2x+1=6⇒x=5/2 si y=7 perechea (5/2;7)
2x+1=7⇒x=3 si y=6 perechea (3;6)
In conditiile in care cerinta este din N elimini variantele cu fractii