Sagot :
A:[tex]\frac{7}{18}.\frac{2}{7}-(\frac{5}{3}-\frac{3}{3})^{2}=\frac{1}{9}- \frac{4}{9}=-\frac{3}{9}=\frac{1}{3}[/tex]
B:[tex]\frac{3.10^{2}.5.10^{4}}{12.10^{9}} = 1,25.10^{-3}[/tex]
C: 2rac(5) + 10rac(5) -7rac(5) = 5rac(5)
A=(7/18)*(2/3)-(5/3-1)²
=(7/18)*(2/3)›14/126›(1/9)*(14/14)
=1/9-4/9
=-3/9
=1/3