Sagot :
Bonjour !
Nombre 7.:
1) a => 7x3/7=21/7=3
b => 3+5=8
c => 8:1/5= 8×5 = 40
2)Nombre 28/15
a) 28/15×3/7 = 4/5
b) 4/5+5 = 4/5+25/5=29/5
c) 29/5 : 1/5 = 29/5 × 5 = 145/5 = 29
3) Soit le nombre cherché, on a :
x*3/7 = 3x/7+5:1/5 = 0
3x/7 + 35/7:1/5 = 0
3x/7 +175/7 = 0
3x = - 25
x = - 25/3
Vérification :
3x/7+5:1/5 = 0
3(-25/3)+5:1/5 = 0
-75/3+25 = 0
Bonne journée.
1) 7x3/7=21/7=3
3+5=8
8:1/5= 8×5 = 40
2) 28/15×3/7 = 4/5
4/5+5 = 4/5+25/5=29/5
29/5 : 1/5 = 29/5 × 5 = 145/5 = 29
3) x*3/7 = 3x/7+5:1/5 = 0
3x/7 + 35/7:1/5 = 0
3x/7 +175/7 = 0
3x = - 25
x = - 25/3
On vérifie comme ceci :
3x/7+5:1/5 = 0
3(-25/3)+5:1/5 = 0
-75/3+25 = 0