Question

Please help thank youuu

Answer 1

Answers are in bold

• f(5) = -77
• g(-4) = -4

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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...

$f(\text{x}) = -3\text{x}^2 - 2\\\\f(5) = -3(5)^2 - 2\\\\f(5) = -3(25) - 2\\\\f(5) = -75 - 2\\\\f(5) = -77$

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:

$g(\text{x}) = 2\text{x} +4\\\\g(-4) = 2(-4) +4\\\\g(-4) = -8 +4\\\\g(-4) = -4$

You can use a graphing calculator or graphing software (eg: Desmos or GeoGebra) to confirm these answers quickly.