Answer:
Step-by-step explanation:
15a²bc = 3·5·a²·b·c
20ab²c = 2²·5·a·b²·c
25bc³ = 5²·b·c³
greatest common factor: 5bc
(-15a²bc + 20ab²c - 25bc³)÷(5bc) = -3a² + 4ab - 5c²
-15a²bc + 20ab²c - 25bc³ = (-3a² + 4ab - 5c²)(5bc)
x = 5
12x - 6 + 6 = 54 + 6
12x = 60
12/12 = 60/12
X = 5