bonjour 3+5/4×(2-1/5) 25/17÷15/14-11/3 merci d'avance

bonjour

3+5/4×(2-1/5)
3+5/4 x(10/5-1/5)
3+5/4 x9/5
3+9/4
12/4+9/4
21/4

25/17÷15/14-11/3
25/17 x14/15  -11/3
5/17x14/3 -11/3
70/ 51 -11/3
70/51 -187/51
- 117/51

Bonsoir,

3+5/4×(2-1/5)
= 3 + 5/4 x (2 x 5 / 1 x 5 - 1/5)
= 3 + 5/4 x (10/5 - 1/5)
= 3 + 5/4 x 9/5
= 3 + 45/20
= 3 x 20 / 1 x 20 + 45/20
= 60/20 + 45/20
= 105/20
= 5 x 21 / 5 x 4
= 21/4

25/17÷15/14-11/3
= 25/17 x 14/15 - 11/3
= 350/255 - 11/3
= 350 x 3 / 255 x 3 - 11 x 255 / 3 x 255
= 1050/765 - 2805/765
= - 1755/765
= 45 x - 39 / 45 x 17
= - 39/17