As we did in the previous problem, we need to remove the parenthesis using distributive property so as to be able to combine like terms.
The first paranthesis is positive, so nothing changes as we remove it:
8 j^3 + 9 j^2 + 6 j + 8 - (j^2 + 8)
before removing the second parenthesis, we realize it is preceded by the negative sign of the indicated subtraction. Then as we remove the parenthesis, we flip the signs of all terms inside it:
8 j^3 + 9 j^2 + 6 j + 8 - j^2 - 8
now we combine like terms + 8 and - 8, rendering a zero "0". and we also combine the terms that contain j^2 : 9 j^2 - j^2 = 8 j^2.
Therefore, our final expression becomes:
8 j^3 + 8 j^2 + 6 j