bantuin dong tp pake cara yaaa

12) 2x + 3 = 4x -5
2x - 4x = -3 + 5
-2x = 2
x = -1
2x + 3 = 2(-1) +3
= -2 + 3 = 1

13) A U B = gabungan himpunan A dan B
= {3,4,5,6,7}