Bonjour,
C= 3/4 + 2/5 ×10/3
= 3/4 + 2×5×2/3×5 ( il fait barrer le meme nombre, par exemple ici :5)
= 3/4 + 4/3
= 3×3/4×3 + 4×4/3×4
= 9/12 + 16/12
= 25/12
E= ( 7/8 -2) ÷ (1-3/4)
= (7/8 - 2×8/1×8) ÷ (1×4/1×4 - 3/4)
= (7/8 - 16/8) ÷ (4/4 - 3/4)
= -9/8 ÷ 1/4
= -9/4×2 × 4/1
= -9/2
