Question

Which function will have the greatest value of x equals 80

Answer 1

In order to solve this, we can replace 80 for x into each one of the three given functions, then we identify what value of y is the greatest, like this:

For the first function:

y = 4x

y = 4×80

y = 320

For the second function:

y = x² - 15x + 88

y = 80² - 15×80 + 88

y= 6400 - 1200 + 88

y = 5288

For the third function:

`\begin{gathered} y=1.1135^(80) \\ y=5435.23 \end{gathered}`

As you can see, at x = 80 the function that has the greatest value is the third one.