Question

化简：(a^2-2b)(a^2+3b)-3a^2(a^2+2b)+(5a^2-2b)(-2b-5a^2)+26a^4

Answer 1

(a^2-2b)(a^2+3b)-3a^2(a^2+2b)+(5a^2-2b)(-2b-5a^2)+26a^4

=a^4+a²b-6b²-3a^4-6a²b+4b²-25a^4+26a^4

=-a^4-5a²b-2b²