4*(2-3x)+7*(6x+1)-9*(9x+4)=30
8 - 12x + 42x + 7 - 81x -36 = 30 8 + 7 - 30 - 36 = 81x + 12x -42x 51x = 51 x = 51/51 x = 1
ой х= -1
-51x = 51; x = 51/-51; x = - 1