Réponse:
[tex] - \frac{2}{5} \div \frac{3}{15 } + \frac{12}{15 } = - \frac{2}{5} \times \frac{15}{3} + \frac{12}{15 } \\ = - 2 + \frac{12}{15} \\ = \frac{ - 2 \times 15 + 12}{15} \\ = \frac{ - 30 + 12}{15} \\ = - \frac{18}{15} \\ = - \frac{6}{5} [/tex]
B= 9/2 -5/2 / 15/8
=9/2-5/2*8/15
=9/2-4/3
=(9*3-4*2)/2*3
=(27-8)/6
=19/6
