Bài 4: Phân tích đa thức thành nhân tử
Bài 5 trang 25 Toán 8 tập 1
<p><strong>B&agrave;i 5 trang 25 To&aacute;n 8 Tập 1:&nbsp;</strong>Ph&acirc;n t&iacute;ch c&aacute;c đa thức sau th&agrave;nh nh&acirc;n tử:</p> <p>a) 4x<sup>3</sup>&nbsp;&ndash; 16x;</p> <p>b) x<sup>4</sup>&nbsp;&ndash; y<sup>4</sup>;</p> <p>c) xy<sup>2</sup>&nbsp;+ x<sup>2</sup>y +&nbsp;<span id="MathJax-Element-1-Frame" class="mjx-chtml MathJax_CHTML" style="box-sizing: border-box; display: inline-block; line-height: 0; text-indent: 0px; text-align: left; text-transform: none; font-style: normal; font-weight: normal; font-size: 21.78px; letter-spacing: normal; overflow-wrap: normal; word-spacing: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; margin: 0px; padding: 1px 0px; position: relative;" tabindex="0" role="presentation" data-mathml="&lt;math xmlns=&quot;http://www.w3.org/1998/Math/MathML&quot;&gt;&lt;mfrac&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/mfrac&gt;&lt;/math&gt;"><span id="MJXc-Node-1" class="mjx-math" aria-hidden="true"><span id="MJXc-Node-2" class="mjx-mrow"><span id="MJXc-Node-3" class="mjx-mfrac"><span class="mjx-box MJXc-stacked"><span class="mjx-numerator"><span id="MJXc-Node-4" class="mjx-mn"><span class="mjx-char MJXc-TeX-main-R">1</span></span></span><span class="mjx-denominator"><span id="MJXc-Node-5" class="mjx-mn"><span class="mjx-char MJXc-TeX-main-R">4</span></span></span></span></span></span></span><span class="MJX_Assistive_MathML" role="presentation"><math xmlns="http://www.w3.org/1998/Math/MathML"><mfrac><mn>1</mn><mn>4</mn></mfrac></math></span></span>y<sup>3</sup>;</p> <p>d) x<sup>2</sup>&nbsp;+ 2x &ndash; y<sup>2</sup>&nbsp;+ 1.</p> <div class="teads-adCall">&nbsp;</div> <p><strong>Lời giải:</strong></p> <p>a) 4x<sup>3</sup>&nbsp;&ndash; 16x</p> <p>= 4x(x<sup>2</sup>&nbsp;&ndash; 4)</p> <p>= 4x(x<sup>2</sup>&nbsp;&ndash; 2<sup>2</sup>)</p> <p>= 4x(x + 2)(x &ndash; 2).</p> <p><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/03082023/a0d8f4ad-ffb8-4e70-811a-c9200fc1acc8.PNG" /></p>
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