Sulky

Verified answer

Bonsoir, 

A = (1/2 + 4/3) × 6/5
A = (3/6 + 8/6) x 6/5
A = 11/6 x 6/5
Simplification par 6
A = 11/5

B = - 2/5 × (2/7 - 1/3)
B = - 2/5 x (6/21 - 7/21)
B = - 2/5 x (- 1/21)
B = 2/105

C = 2 - 5/2 ÷ 15/4
C = 2 - 5/2 x 4/15
C = 2 - (5 x 2 x 2)/(2 x 3 x 5)
Simplification par 2 et 5
C = 2 - 2/3
C = 6/3 - 2/3
C = 4/3

D = 1 + 2/5 + 3/4
D = 20/20 + 8/20 + 15/20
D = (20 + 8 + 15)/20
D = 43/20

MonsieurFirdown

Verified answer

Bonjour

♧ On a :

A = (1/2 + 4/3) × 6/5
A = ((1×3)/(2×3) + (4×2)/(3×2)) × 6/5
A = (3/6 + 8/6) × 6/5
A = 11/6 × 6/5
A = 66/30 = 11/5

B = -2/5 × (2/7 - 1/3)
B = -2/5 × ((2×3)/(7×3) - (1×7)/(3×7))
B = -2/5 × (6/21 - 7/21)
B = -2/5 × (-1/21)
B = 2/105

C = 2 - 5/2 ÷ 15/4
--> la division est prioritaire on a donc :
C = 2 - (5/2 ÷ 15/4)
--> Diviser par une fraction revient à multiplier par son inverse on a donc :
C = 2 - (5/2 × 4/15)
C = 2 - 20/30
C = 60/30 - 20/30
C = 40/30 = 4/3

D = 1 + 2/5 + 3/4
B = 20/20 + 8/20 + 15/20
B = 43/20

Voilà ^^