Answer:
The value of f(x) when x=-1 is 0.5
Therefore 
Step-by-step explanation:
Given that y=f(x)=
to find the f(x) when x=-1 :
That is to find f(-1)
Put x=-1 in the given function f(x)=



Therefore 
The value of f(x) when x=-1 is 0.5
Answer:

Step-by-step explanation:
Though it is not what you have written, we think you want to simplify ...

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When writing a fraction in plain text, parentheses are needed around the entire denominator. The order of operations tells you that a/bc = (a/b)c, not a/(bc).
Answer:
a. A minimum of 300
Step-by-step explanation:
If her bill is $142 then it is a sum of the flat rate plus the money she pays for all the smses she sent. As an equation, it can be expressed this way
106 + 0.12x = 142 where x is the number of smses
0.12x = 36
x = 300 smses
So if we were told that she pays $142 per month, we'd know that she sends 300 smses. But we are told she pays AT LEAST $142 so there is a possibility that she sends even more than 300 smses