nomor 2 dan 3 pakai cara jalan

2). 3x -1 < x-2
= 3x -x < -2 + 1
= 2x < -1
= x < -1/2

3). 5x -4 = x + 20
5x -x = 20+ 4
4x = 24
x = 24/4
x = 6