Nilai p-20 adalah....

1/2 (3p-12) = 12 +12/5p
3/2p - 6 = 12 +12/5 p
3/2 p -12/5 p = 12 + 6
[tex] \frac{15-24}{10}p = 18 \\ \frac{-9}{10}p = 18 \\ p = 18: \frac{-9}{10} = 18 x \frac{10}{-9} = -20[/tex]
p-20 = -20-20 = -40

1/2(3p-12) =12+12/5p
3/2p-6 =12+12/5p
3/2p-12/5p=12+6
-9/10p =18
p=18×10/9
p=-20

Jadi
p-20=20-20=0