Calculs Fractionnaires : A = 3/7-2/7×21/8  |  B = 5/4-2/3×9/16  |  C = (2+2/3)×(4/5-2/3)  |  D = 1-(1/4+3/4×4/5) Calculs & Puissances : E = -3×(5-3×2)³    |  F

Calculs Fractionnaires:
A = 3/7-2/7×21/8
=3/7-42/56
=24/56-42/56
=-18/56
=-9/28

B = 5/4-2/3×9/16 
=5/4-18/48
=5/4-9/24
=30/24-9/24
=21/24
=7/8

C = (2+2/3)×(4/5-2/3)
=(6/3+2/3)*(12/15-10/15)
=8/3*2/15
=16/45

D = 1-(1/4+3/4×4/5)
=1-(5/20+12/20)
=20/20-17/20
=3/20

Calculs & Puissances:
E = -3×(5-3×2)³ 
=-3*(5-6)²
=-3*(-1)²
=-3*1
=-3

F = (15-6×3)×(7-6-2×4)²
=(15-18)*(1-8)²
=-3*(-7)²
=-3*49
=-147

A = 3/7-2/7×21/8
[tex] \frac{3}{7} - \frac{2}{7} [/tex] × [tex] \frac{21}{8} [/tex]
[tex] \frac{1}{7} [/tex] × [tex] \frac{21}{8} =[/tex] [tex] \frac{21}{56} = \frac{3}{8} [/tex]

B = 5/4-2/3×9/16
B =[tex] \frac{5}{4} - \frac{2}{3} [/tex] × [tex] \frac{4}{5} - \frac{2}{3} [/tex]
B =[tex] \frac{15}{12} - \frac{8}{12} [/tex] × [tex] \frac{12}{15} - \frac{10}{15} [/tex]
B = [tex] \frac{7}{12} [/tex] × [tex] \frac{2}{15} [/tex]
B = [tex] \frac{14}{180} [/tex]
B = [tex] \frac{7}{90} [/tex]

C = (2+2/3)×(4/5-2/3)
C = [tex]( \frac{6}{3} + \frac{2}{3} × (\frac{12}{15} - \frac{10}{15}[/tex]
C = [tex] \frac{8}{3} [/tex] × [tex] \frac{2}{15} [/tex]
C = [tex] \frac{16}{45} [/tex]

D = 1-(1/4+3/4×4/5)
D = [tex]1 - ( \frac{1}{4} + \frac{3}{4} × \frac{4}{5}) [/tex]
D = [tex]1- (1 × \frac{4}{5}) [/tex]
D = [tex] \frac{1}{5} [/tex]