diketahui 5(x + 3) - 25= 3(4x -1) maka nilai x - 1 adalah... tolong jawab pake cara nya y

persamaan (mencari n x)

5(x + 3) - 25= 3(4x -1)
5x + 15 - 25 = 12x - 3
5x - 10 = 12x - 3
5x - 12x = -3 + 10
-7x = 7
x = 7/-7
x = -1

nilai x - 1
= -1 - 1
= -2