Réponses

2014-05-13T13:45:36+02:00
49a)
x/5=7/2
⇔2x=5*7
⇔2x=35
x=35/2

49b)
(3-x)/2=(x+1)/3
⇔3(3-x)=2(x+1)
⇔9-3x=2x+2
⇔9-2=3x+2x
⇔7=5x
⇔x=7/5