bonjour
A=[tex] \frac{2}{3} - \frac{5}{13} / \frac{10}{6} = \frac{26}{39} - \frac{15}{39} = \frac{11}{39} * \frac{6}{10} = \frac{66}{390} = \frac{11*6}{65*6} = \frac{11}{65} [/tex]
B=5*10^-7*3.9*10^4
______________ =5*3.9 19.5 *10^-7+4-(-5)
1.3*10^-5 ____= ___ =15*10^2=1500
1.3 1.3
b)=1.5*10^3
