若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)

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若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)若a+b=3,ab=-2,求(5a-5b-ab)-(4a

若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)
若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)

若a+b=3,ab=-2,求(5a-5b-ab)-(4a-6b-3ab)
(5a-5b-ab)-(4a-6b-3ab)
=5a-5b-ab-4a+6b+3ab
=a+b+2ab
=3-2x2
=-1

(5a-5b-ab)-(4a-6b-3ab)
原式=5a-5b-ab-4a+6b+3ab
=a+b+2ab
a+b=3,ab=-2 代入上式得:
3-4=-1
∴(5a-5b-ab)-(4a-6b-3ab)=-1

原式=5a-5b-ab-4a+6b+3ab=a+b+2ab=3-4=-1

(5a-5b-ab)-(4a-6b-3ab)
=5a-5b-ab-4a+6b+3ab
=a+b+2ab
=3+2*(-2)
=3-4
=-1