Bonjour
[tex]A = 13 - 2^4\times ( 5 - 2\times 4)^2\\\\A = 13 - 16\times ( 5 - 8)^2\\\\A = 13 - 16\times (-3)^2\\\\A = 13 - 16\times 9\\\\A = 13 - 144\\\\A=-131[/tex]
[tex]B = 4\times8 - \dfrac{3^2}{7}\times2^3 - ( 5\times2 )^2\\\\B = 32 - \dfrac{9}{7}\times8 - 10^2\\\\B = 32 - \dfrac{72}{7} - 100\\\\B = -68 - \dfrac{72}{7}\\\\B = \dfrac{-68\times7}{7} - \dfrac{72}{7}\\\\B = \dfrac{-476}{7} - \dfrac{72}{7}\\\\B=\dfrac{-548}{7}[/tex]