In 3 years, a gym membership went up from 6,400 to 8,400. Write an expression that shows how to find the percent of increase. Then find the percent of increase.

change = (new/old - 1) * 100% 31.25%

Step-by-step explanation:

Percent change is found using the formula ...

percent change = ((new value) - (old value)) / (old value) * 100%

This can be divided out to be ...

percent change = ((new value) / (old value) - 1) * 100%

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For your numbers, the change is ...

percent change = (8400 - 6400) / 6400 * 100% = 31.25%