(−p−4q−9)−(−8p−9q−8)

Sure, let's solve this step by step:

1. First, distribute the negative sign in the second parentheses to each term inside it. This will change the sign of each term. So, the equation becomes: (−p−4q−9) - (-8p) - (-9q) - (-8)

2. Now, subtracting a negative number is the same as adding a positive number. So, the equation becomes: (−p−4q−9) + 8p + 9q + 8

3. Now, combine like terms. This means adding or subtracting the coefficients (the numbers in front of the variables) of the like terms. So, the equation becomes: (-1p + 8p) + (-4q + 9q) + (-9 + 8)

4. Now, simplify the equation by performing the addition and subtraction operations: 7p + 5q - 1

So, the simplified form of the equation "(−p−4q−9)−(−8p−9q−8)" is "7p + 5q - 1".