svp aider moi a faire mon devoir merci

1 + 1/6 + 1/18 + 1/72 + 1/120
= 1 + (1 x 60)/(6 x 60) + (1 x 20)/(18 x 20) + (1 x 5)/(72 x 5) + (1 x 3)/(120 x 3)
= 360/360 + 60/360 + 20/360 + 5/360 + 3/360
= (360 + 60 + 20 + 5 + 3)/360
= 448/360
= (8 x 56)/(8 x 45)
= 56/45