Sagot :
Soit x le nombre recherché
67 = x*-8 + 11
67 - 11 = -8x + 11 -11
56 = -8x
56/8 = -8x/8
7 = -x
x = -7
67 = x*-8 + 11
67 - 11 = -8x + 11 -11
56 = -8x
56/8 = -8x/8
7 = -x
x = -7