Répondre :
A = 2 + 3/5 : 7/4
= 2 + 3/5 x 4 /7
= 2 + 12 /35
= ( 2 *35 ) / 35 + 12 /35
= 70/35 + 12/35
= 82 /35
B = - 7 /9 - 8 /11 : 9
= - 7 - 8 /11 x 1 /9
= - 7 - 8 /99
= ( - 7 * 99 ) /99 - 8 / 99
= - 693/99 - 8 /99
= - 685/99
C = 2/3 - 5 /3 : 20/21
= 2/3 - 5 /3 x 21/20
= 2/3 - 105 / 60
= 2 /3 - 7/4
= 8/12 - 21 /12
= - 13 /12
D = 7/9 : ( 1 /3 - 2 )
= 7 /9 : ( 1/3 - 6/3 )
= 7/9 : - 5 /3
= 7/9 x - 3 /5
= - 21 / 45
= - 7 / 15
A = ( 2 x 3 /7 ) : ( 5/3 - 1 )
= 6 /7 : ( 5/3 - 3 /3 )
= 6 /7 : 2 /3
= 6 /7 x3 /2
= 18/14
= 9 /7
B = ( 2 + 3 /4 ) : ( 3/4 - 5 )
= ( 8/4 + 3 /4 ) : ( 3/4 - 20/4 )
= 11/4 : - 17/4
= 11/4 x - 4/17
= - 44/68
= - 11 / 17
C = ( 4 /3 - 2/5 ) : ( 5 /2 + 3 /10 )
= ( 20/15 - 6 /15 ) : ( 25/10 + 3 /10 )
= 14 /15 : 28/10
= 14/15 x 10 / 28
= 140 / 420
= 1/3
Bonjour
A = 2 + 3/5 : 7/4
A = 2 + 3/5 x 4/7
À = 2 + (3 x 4)/(5 x 7)
À = 2 + 12/35
À = (2 x 35)/35 + 12/35
À = 70/35 + 12/35
À = 82/35
B = -7/9 - 8/11 : 9
B = -7/9 - 8/11 x 1/9
B = -7/9 - 8/(11 x 9)
B = -7/9 - 8/99
B = (-7 x 11)/(9 x 11) - 8/99
B = -77/99 - 8/99
B = -85/99
C = 2/3 - 5/3 : 20/21
C = 2/3 - 5/3 x 21/20
C = 2/3 - (5 x 21)/(3 x 20)
C = 2/3 - (5 x 7 x 3)/(3 x 5 x 4)
C = 2/3 - 7/4
C = (2 x 4)/(3 x 4) - (7 x 3)/(4 x 3)
C = 8/12 - 21/12
C = (-13/12)
D = 7/9 : (1/3 - 2)
D = 7/9 : (1/3 - (2 x 3)/3)
D = 7/9 : (1/3 - 6/3)
D = 7/9 : (-5/3)
D = 7/9 x (-3/5)
D = (7 x (-3))/(9 x 5)
D = (-7 x 3)/(3 x 3 x 5)
D = -7/15
A = (2 x 3/7) / (5/3 - 1)
À = (6/7) / (5/3 - 3/3)
À = (6/7) / (2/3)
À = 6/7 x 3/2
À = (6 x 3)/(7 x 2)
À = (2 x 3 x 3)/(7 x 2)
À = 9/7
B = (2 + 3/4) / (3/4 - 5)
B = (8/4 + 3/4) / (3/4 - 20/4)
B = 11/4 / (-17/4)
B = 11/4 x (-4/17)
B = 4/4 x (-11/17)
B = -11/17
C = (4/3 - 2/5) / (5/2 + 3/10)
C = (20/15 - 6/15) / (25/10 + 3/10)
C = 14/15 / 28/10
C = 14/15 x 10/28
C = 14/28 x 10/15
C = 14/(2 x 14) x (2 x 5)/(3 x 5)
C = 1/2 x 2/3
C = 2/2 x 1/3
C = 1/3