yg no 4-7 tolong dibantu yah ,,sama cara kerjanya juga

Nomor 4.
A = 3x - 2
B = 2x - 4
A + B = (3x - 2) + (2x - 4)
= 5x - 6
B + A = (2x - 4) + ( 3x - 2)
= 5x - 6

Nomor 5.
A = 2x - 1
B = 1 - x
A + B = (2x - 1) + (1 - x)
= x
B + A = (1 - x) + (2x - 1)
= x

Nomor 6.
A = 3x
B = 2x + 1
A + B = 3x + (2x + 1)
= 5x + 1
B + A = (2x + 1) + 3x
= 5x + 1

Nomor 7.
A = 5
B = 2x - 4
A + B = 5 + ( 2x - 4)
= 2x + 1
B + A = (2x - 4) + 5
= 2x + 1