bonjour
aire rectangle = ( 4 x - 7 ) ( 2 x - 3 )
= 8 x² - 12 x - 14 x + 21
= 8 x² - 26 x + 21
aire carré = ( 2 x - 3 )² = 4 x² - 12 x + 9
8 x²- 26 x + 21 - ( 4 x² - 12 x + 9 ) = 12
8 x² - 26 x + 21 - 4 x² + 12 x - 9 ) = 12
4 x² - 14 x + 12 = 12
4 x² - 14 x = 0
2 x ( 2 x - 7 ) = 0
x = 0 ou 7/2 = 3.5
0 non retenu
solution = 3.5
