1. michelle purchased 25 audio files in january. in february she
purchased 40 audio files. find the percent increase. (lesson 5.1)

Michelle purchased 25 audio files in January. The percent increase is 60%

Solution:

Given Data:

Michelle purchases = 25 audio files in January

Again purchased = 40 audio files in February

We need to find the percent increase for the given data.

Step 1:

Use the formula for percent change ,

Step 2:

First we find the amount of change from the question.

Amount of change = 40 – 25  

By subtracting, we get 15.

Step 3:

substitute the values in formula we get,

Formula percent change = = 0.6  

Percent = 0.6 100 = 60 %.

Result:

Michelle purchased 25 audio files in January. And In February she purchased 40 audio files. Hence the percent increase is 60%.

$450 is the answer.

step-by-step explanation:

30% of 450 = 135

450-135=315

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!