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2012-12-28T21:58:34+01:00

 

 

A = 12x²-10x-48x+40 - (49x²-126x+81)

= 12x² -58x+40+49x²+126x-81

= 61x²+68x -41

 

pour x = -3

A = 61*-3² +68*-3-41

= 61*9-204-41

= 549-245 = 304

 

pour x = 5/6

A = 61*(5/6)²+68*5/6-41

= 61*25/36+340/6-41

= 1525/36 +2040/36-1476/36

= 2089/36

 

pour x = 1/3

A = 61*(1/3)² +68*1/3-41

= 61*1/9+68/3-41

= 61/9 + 204/9-369/9

= 104/9