To find the percentage change from 90 to 75, we need to first calculate the difference between the two numbers.

Step 1: Difference = Final Value - Initial Value

Difference = 75 - 90

Difference = -15

Step 2: Next, we need to find the absolute value of the difference. This is because percentage change is always calculated as a positive value.

Absolute Difference = |Difference|

Absolute Difference = |-15|

Absolute Difference = 15

Step 3: Now, we can calculate the percentage change using the formula:

Percentage Change = (Absolute Difference / Initial Value) x 100

Percentage Change = (15 / 90) x 100

Percentage Change = 16.67%

Therefore, the percentage change from 90 to 75 is -16.67%. This means that there was a decrease of 16.67% from 90 to 75.