Question

The function j(x)=39x represents the number of the jumping jacks j(x) you can do in x minutes how many jumping jacks can you do in 5 minutes

Answer 1

Put x=5 in above function. J(x)= 39x. J(5) = 39x5 = 195.

Answer 2

`195\ jumping\ jacks`

Explanation:

Let

x------> the time in minutes

j(x)----> the number of the jumping jacks

we have

`j(x)=39x`

This is a linear direct variation

The slope is equal to
`m=39(jumping\ jacks)/(minute)`

To find how many jumping jacks can you do in
`5` minutes

Substitute the value of
`x=5\ min` in the function j(x)

so

`j(5)=39(5)=195\ jumping\ jacks`