Ignore the one that is crossed out. I already completed that one but then I got stuck on the others. Please show work. Thank you.
Can you post this as latex instead?
\((2a^2b-5b^3+4a^4b^2)-(7b^3+8a^4b^2-7a^2b)\\ =(2a^2b-5b^3+4a^4b^2)-7b^3-8a^4b^2+7a^2b\\ =(4a^4b^2-8a^4b^2)+(-5b^3-7b^3)+(2a^2b+7a^2b)\\ =-4a^4b^2-12b^3+9a^2b\).