Répondre :

A) 2+3x = 8 >> 3x = 6 >> x = 2.
B) 6x+1 = -11 >> 6x = -12 >> x = -2.
C) 105 = -25x + 30 >> 75 = -25x >> x = -3.
D) -8x + 7 = -49 >> -8x = -56 >> x = 7