Jika p=6,q=-3, dan r=-5.Hitunglah nilai dari a.pq-2qr b.2p²q-4qr² c.(p+q-r)+(p-q-r) d.(2p-3q+25)-(2p+5q-7r) Isilah jawaban berikut dengan benar dan dengan caran

p= 6
q= -3
r= -5

a) 6.5 - 2(-3.-5)
= 30 - 30 = 0

a) pq - 2qr
= q(p - 2r)
= -3(6 - 2.(-5)
= - 3(6 + 10)
= - 3 × 16
= - 48

b) 2p²q - 4qr²
= 2q ( p² - 2r²)
= 2(-3) (6² - 2 . (-5)²)
= - 6 (36 - 50)
= - 6 × (-14)
= 84

c) (p + q - r) - (p - q - r)
= p - p + q + q - r + r
= 2q
= 2(-3)
= - 6

d) (2p - 3q + 25) - (2p + 5q - 7r)
= 2p - 2p - 3q - 5q + 7r + 25
= - 8q + 7r + 25
= - 8(-3) + 7(-5) + 25
= 24 - 35 + 25
= 14