Réponses

2014-01-31T19:37:34+01:00
Bonsoir,

\dfrac{-(42+x)\times36}{2}=3\times\dfrac{36(42-x)}{2}\\\\\dfrac{-(42+x)\times36}{2}=\dfrac{3\times36(42-x)}{2}\\\\-(42+x)\times36=3\times36(42-x)\\\\-(42+x)=3(42-x)\\\\-42-x=126-3x\\\\3x-x=126+42\\\\2x=168\\\\x=84


-10x = 72 + 6x
-10x - 6x = 72
-16x = 72
x = 72/(-16)
x = -4,5


\dfrac{-(x+1)}{3}\times9 + x = 80\\\\\dfrac{-9(x+1)}{3} + x = 80\\\\-3(x+1)+x=80\\\\-3x-3+x=80\\\\-3x+x=80+3\\\\-2x=83\\\\x=\dfrac{83}{-2}\\\\x=-41,5