Réponse:
1)
A=
[tex]1 - ( \frac{2}{3} + \frac{1}{4} ) = 1 - ( \frac{2 \times 4}{3 \times 4} + \frac{1 \times 3}{4 \times 3} ) = 1 - ( \frac{8}{12} + \frac{3}{12} ) = 1 - \frac{11}{12} = \frac{12}{12} - \frac{11}{12} = \frac{1}{12} [/tex]
B=
[tex] \frac{3 - \frac{5}{2} }{1 + \frac{1}{5} } = \frac{ \frac{6}{2} - \frac{5}{2} }{ \frac{5}{5} + \frac{1}{5} } = \frac{\frac{1}{2}}{ \frac{6}{5} } = \frac{1}{2} \times \frac{5}{6} = \frac{5}{12} [/tex]
2)
C=
[tex] \frac{4}{5} \times \frac{35}{8} = \frac{4 \times 5 \times 7}{5 \times 4 \times 2} = \frac{7}{2} [/tex]
3) A+B+C=
[tex] \frac{1}{12} + \frac{5}{12} + \frac{7}{2} = \frac{1}{12} + \frac{5}{12} + \frac{42}{12} = \frac{48}{12} = \frac{12 \times4}{12} = 4[/tex]
