Answer:
3rd option
Step-by-step explanation:
x < 7
means that x cannot equal 7 but all values less than 7
since not equal at either end of interval use parenthesis, not brackets , then
(- ∞ , 7 ) ← is the required interval
1/9 or 11/100
Hope that helps
Answer: i) f(-9)= 66
ii)
.
iii) 
Step-by-step explanation:
The given function :
.
i) For f(-9) , the independent variable is x= -9.
Put x= -9 in given function , we get


Thus , f(-9)= 66
ii) For f(x+1) , the independent variable is x= x+1.
Replace x by x+1 in given function , we get
.
![[\because\ (a+b)^2=(a^2+b^2+2ab)]](https://tex.z-dn.net/?f=%5B%5Cbecause%5C%20%28a%2Bb%29%5E2%3D%28a%5E2%2Bb%5E2%2B2ab%29%5D)


Thus ,
.
iii)For f(-x) , the independent variable is x=-x.
Replace x by -x in given function , we get
.
[∵ (+)(-)=(-)]
Thus , 
Isn't it already in standard form?