Réponses

2014-05-07T18:26:25+02:00
(x+0,5)(-x+2,5)=0 

x+0.5 = 0      -x +2.5 = 0
x = -0.5           -x = -2.5 
x = -1/2            x = 2.5 = 25/10 = 5/2



-(x-1)²+2,25=0
-(x-1)² + 1.125² = 0
- (x-1 +1.125) (x-1+1.125) = 0
-(x +0.125) (x +0.125) = 0

-x -0.125 = 0    ou x +0.125 =0
-x = 0.125              x = -0.125
x = 0.125

donc une sule solution x = 0.125 = 125/1000  = 25/200 = 5/ 40