Final answer:
To find the percent change of x when we got 3.5x, we can use the formula ((Final Value - Initial Value) / Initial Value) * 100. In this case, x was changed by 250%.
Step-by-step explanation:
To find the percent change of x, we need to compare the initial value of x to the final value of 3.5x. The formula to calculate percent change is:
Percent Change = ((Final Value - Initial Value) / Initial Value) * 100
In this case, the initial value is x and the final value is 3.5x.
Percent Change = ((3.5x - x) / x) * 100
= (2.5x / x) * 100
= 250%
Therefore, x was changed by 250%.