Simplify the expression by combining like terms. Write the terms from the highest to the lowest
power of the variable.
-9a^2 - 17a^2 - 8a - 8 - 12a^2 - 17 - 9a + 7a

-38a^2 - 10a - 25

Step-by-step explanation:

The highest power of a is a^2.  Combine the a^2 terms:

(-9 - 17 - 12)a^2 = -38a^2

Now combine the a terms:

(-8 - 9 + 7)a = -10a

Finally, combine the constants:  -8 - 17 = -25

Summing up these three results, we get:

-38a^2 - 10a - 25

addition

step-by-step explanation: