Bài 4: Bất Phương Trình Bậc Nhất Một Ẩn
Hướng dẫn giải Bài 22 (Trang 47 SGK Toán Đại số 8, Tập 2)
<p>Giải c&aacute;c bất phương tr&igrave;nh sau v&agrave; biểu diễn tập nghiệm tr&ecirc;n trục số:</p> <p>a) 1,2x &lt; -6;<span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span>b) 3x+4 &gt; 2x+3</p> <p><em><strong>Hướng dẫn:</strong></em></p> <p>a)&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mn>1</mn><mo>,</mo><mn>2</mn><mi>x</mi><mo>&#60;</mo><mo>-</mo><mn>6</mn><mo>&#160;</mo><mo>&#8660;</mo><mo>&#160;</mo><mi>x</mi><mo>&#60;</mo><mfrac><mrow><mo>-</mo><mn>6</mn></mrow><mrow><mn>1</mn><mo>,</mo><mn>2</mn></mrow></mfrac><mo>&#8660;</mo><mi>x</mi><mo>&#60;</mo><mo>-</mo><mn>5</mn></math><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span></p> <p><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/12032022/screenshot-2022-03-12-094724-rgEyem.png" /></p> <p>b)&nbsp;<math xmlns="http://www.w3.org/1998/Math/MathML"><mn>3</mn><mi>x</mi><mo>+</mo><mn>4</mn><mo>&#62;</mo><mn>2</mn><mi>x</mi><mo>+</mo><mn>3</mn><mo>&#160;</mo><mo>&#8660;</mo><mo>&#160;</mo><mn>3</mn><mi>x</mi><mo>-</mo><mn>2</mn><mi>x</mi><mo>&#62;</mo><mn>3</mn><mo>-</mo><mn>4</mn><mo>&#160;</mo><mo>&#8660;</mo><mo>&#160;</mo><mi>x</mi><mo>&#62;</mo><mo>-</mo><mn>1</mn></math></p> <p><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><span class="mce-nbsp-wrap" contenteditable="false">&nbsp;&nbsp;&nbsp;</span><img class="wscnph" style="max-width: 100%;" src="https://static.colearn.vn:8413/v1.0/upload/library/12032022/screenshot-2022-03-12-094847-UKdS7B.png" /></p>
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