Tolong di bantu yaa jangan lupa pake rumusnya

P = 7a-8b-c
Q = -3a+2b-6c

Soal: P - 2Q
Jawab :
P - 2Q
= 7a-8b-c - 2(-3a+2b-6c)
= 7a-8b-c + 6a-4b+12c
= 13a-12b+11c

Hasilnya : 13a-12b+11c