Answers are in bold
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Step-by-step explanation:
The x is a placeholder for a number.
When we say f(5), we mean f(x) when x = 5
So we'll replace every copy of x with 5 like so...
Notice how I used the order of operations PEMDAS after x = 5 was plugged in.
A similar situation happens with g(-4). We'll plug x = -4 into g(x) to get the following:
You can use a graphing calculator or graphing software (eg: Desmos or GeoGebra) to confirm these answers quickly.