12 икс-7×( икс+4)=26-4 икс
12Х-7(Х+4)=26-4Х 12Х-7Х-28=26-4Х 5Х-28=26-4Х 5Х+4Х=28+26 9Х=54 Х=54 : 9 Х= 6
12x -7(x+4) =26 -4x 12x -7x -28 =26 -4x 5x -28 =26 -4x 5x+4x = 26+28 9x = 54 x =54/9 x =6