[tex]bonjour\\\\A = ( 7 x - 5 )^{2} - ( 3 x - 2 ) ^{2} \\= 49 x^{2} - 70 x + 25 - ( 9 x^{2} - 12 x + 4 )\\= 49 x^{2} - 70 x + 25 - 9 x^{2} + 12 x - 4 \\= 40 x^{2} - 58 x + 21 \\\\\\A = ( 7 x - 5 + 3 x - 2 ) ( 7 x - 5 - 3 x + 2 )\\A = ( 10 x - 7 ) ( 4 x - 3 ) \\A = 0 \\pour \\x = 7/10 \\ou\\x = 3/4 \\S = { 7/10 ; 3/4 } \\[/tex]
