Question

因式分解3、x4十7x2一8.4、a4一a3十a2一a.5.(ax十by)2十(bx一ay)2

Answer 1

3、x4十7x2一8

=﹙x²＋8﹚﹙x²－1﹚

=﹙x²＋8﹚﹙x＋1﹚﹙x－1﹚

4、a4一a3十a2一a

=a³﹙a－1﹚＋a﹙a－1﹚

=a﹙a－1﹚﹙a²＋1﹚

5、(ax十by)2十(bx一ay)2

=a²x²＋2abxy＋b²y²＋b²x²－2abxy＋a²y²

=a²x²＋b²y²＋b²x²＋a²y²

=﹙a²x²＋a²y²﹚＋﹙b²y²＋b²x²﹚

=a²﹙x²＋y²﹚＋b²﹙y²＋x²﹚

=﹙y²＋x²﹚﹙a²＋b²﹚