Question

求值：(1)已知ab²=6,求ab（a²b⁵-ab³-b）的值； （2）3（3

Answer 1

-ab(a²b^5-ab³-b)

=-ab²(a²b^4-ab²-1)

=6(6^2+6-1)

=6*31

=186

a=1,b=-1/2,ab=-1/2

2(3a^2+2ab-b^2)*(-ab)-3a^2(ab-b^2)

=-2ab(3a^2+2ab-b^2)-3aab(a-b)

=3a^2+2ab-b^2+3a/2(a-b)

=3a^2-1-b^2+3a^2/2-3ab/2

=9a^2/2-b^2-1/4

=9/2-1/4-1/4

=9/2-1/2

=4