Answer:
i think its every 90 minutes but I could be wrong.
Step-by-step explanation:
x²-3x+2=0
x²-2x-x+2=0
(x²-2x)(-x+2)=0
x(x-2)-1(x-2)=0
(x-2)(x-1)=0
x-2=0 or x-1=0
x=2 or x=1
try x equals nine I am sure
