Salut
Réponse :
a ) 2 ( 6 - 2x ) + 5 = 3 ( 4x + 1 )
⇔ 12 - 4x + 5 = 12x + 3
⇔ 17 - 4x = 12x + 3
⇔ - 4x - 12x = 3 - 17
⇔ - 16x / ( - 16 ) = - 14 / ( - 16 )
⇔ x = 7 / 8
b ) ( 6 - 2x ) / 2 = 10
⇔ ( ( 6 - 2x ) / 2 ) x 2 = 10 x 2
⇔ 6 - 2x = 20
⇔ - 2x = 14
⇔ - 2x / ( - 2 ) = 14 / ( - 2 )
⇔ x = - 7
c ) ( 6 - 2x ) / 4 = ( 7 + 3x ) / 2
⇔ ( ( 6 - 2x ) / 4 ) x 4 = ( ( 7 + 3x ) / 2 ) x 4
⇔ 6 - 2x = 14 + 6x
⇔ - 8x = 8
⇔ x = - 1
Voilà
