Isirayn

Xisaab ahaan isirayn waa furfurid: fansaar hal tibix lambar $n$ ururka tirsiimo $T=$ $\{1,2,3,4,5\dots \}$ sidoo kale waxay yeelan kartaan dhowr tibix ( $n=a_{0}\times a_{1}\times a_{2}\times a_{3}\times \dots$ ).

Tara kasta oo idil waxaa lagu muujin karaa dhibco. Tilmaan ahaan 6 waxaa lagu muujin karaa siyaabahaa

...... ama :::: Tirooyinka u dhigmi kara laydi ahaan ayaa ah tirooyin leh isirro maratal tirada 12 = 6 X 2 = 3 X 4

Raadinta isirka ax + by + ay + bx

Furfuris: ax + by + ay + bx = ax + bx + ay + by

                            Xeerka kala hormarinta isugaynta
                           = ( ax + bx) + ( ay + by)
                           Xeerka hormagalinta isugaynta
                          = x(a + b)  + y (a + b)
                          Xeerka kala dhigga iskudhufashada ee isugaynta
                         = (a + b) (x + y)
                         Xeerka kala dhigga iskudhufashada ee isugeynta
Markaa ax + by + ay + bx = (a + b) (x + y)

portal Xisaab