Question

please help asap!a. if the input is -8, what is the output?b. if the output was 21, what was the input?

Answer 1

a) The output is 45

b) The input was -4

Here, we want to use the relationship between the input and the output to answer the questions

While x is our input, f(x) is given as our output

The relationship between the two is given as;

`f(x)\text{ = -6x-3}`

a) Here, we have an input, and we want to get the output

To solve this, we just need to substitute the value of -8 for x in the relation

We have this as follows;

`\begin{gathered} f(-8)\text{ = -6(-8)-3} \\ f(-8)\text{ = 48-3 = 45} \end{gathered}`

b) Here, we have the output, but we want to get the input

What this simply mean is that we are to find the value of x

We simply substitute 21 for f(x)

Thus, we have;

`\begin{gathered} 21\text{ = -6x-3} \\ 21\text{ + 3 = -6x} \\ \\ -6x\text{ = 24} \\ \\ x\text{ = }(24)/(-6) \\ \\ x\text{ = -4} \end{gathered}`