Bonsoir,
A= 2/5+3/4×7/15
= 2/5+1/4×7/5
= 2/5+7/20
= 3/4 ou 0,75
B= (2/3)carré +1/5×4/3
= 4/9+1/5×4/3
= 4/9+4/15
=32/45 ou 0,71
C= 3carré/2+7/5×8/3
= 9/2+56/15
= 247/30
D= 5/3÷3/4+7/8
= 5/3×4/3+7/8
= 20/9+7/8
= 223/72
E= 2/3-1/2=1/6 et 5/4-4/5=9/20
=1/6/9/20
=10/27
F=7/4-3/5=23/20 et 7/5-3/4=13/20
=23/20/13/20
=23/13
Voilà j'espère que cela t'aura aidé bonne soirée