bonjour
10 ( x + 7) ( x - 5) = 3 x ( x + 7 )
10 ( x + 7 ) ( x - 5) - 3 x ( x + 7) = 0
( x + 7 ) ( 10 x - 50 - 3 x ) = 0
( x + 7 ) ( 7 x - 50) = 0
x = - 7 ou 50/7
( 7 x - 5)² = 16
( 7 x - 5 )² - 16 = 0
( 7 x - 5 - 4 ) ( 7 x - 5 + 4 ) = 0
( 7 x - 9 ) ( 7 x - 1 ) = 0
x = 9/7 pu 1/7