3(2x + 1) - 10 = 2(x - 3) + 11 =
=6x + 3 - 10 = 2x - 6 + 11
=6x - 7 = 2x + 5
=6x - 2x = 5 + 7
=4x = 12
x = 12 : 4
x = 3