數學m2一問. 10點:}

1. for |x-1|=-2since |x-1|>=0thus the equation has no soulution.
佢果到話the absolute value of a no. must be non-nagative
我唔明佢話果個absolute value 係指x-1定-2
點解唔可以咁樣solve|x-1|=-2
x-1=-2 or -x+1=-2
x=-1 or x=3

2.solve the following equation, where n is a positive integer
n
C <-THIS IS factorial notation
n-3
唔識做,想要詳細步驟thz!
3. let y=f(X) br a function such that for any real numbers a and b,
f(ab)=F(a)+f(b).
(a). find the value of f(1)and f(-1).
(b). hence prove that y=f(x) is an even function.