Bài 1: Số vô tỉ. Căn bậc hai số học
<div data-v-a7c68f28=""><span data-v-a7c68f28="">Hướng dẫn giải Bài 4 (Trang 35, SGK Toán 7, Bộ Cánh Diều, Tập 1)</span></div>
<p><strong>B&agrave;i 4 (Trang 35 SGK To&aacute;n 7 - Bộ C&aacute;nh Diều, Tập 1):</strong></p> <p>T&iacute;nh gi&aacute; trị của c&aacute;c biểu thức:</p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>a</mi><mo>)</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>49</mn></msqrt><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>64</mn></msqrt><mo>;</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>b</mi><mo>)</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>36</mn></msqrt><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>81</mn></msqrt><mo>;</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>c</mi><mo>)</mo><mo>&#160;</mo><mn>8</mn><mo>.</mo><msqrt><mn>9</mn><mo>&#160;</mo></msqrt><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><msqrt><mn>64</mn></msqrt><mo>;</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>d</mi><mo>)</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>.</mo><msqrt><mn>400</mn><mo>&#160;</mo></msqrt><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>2</mn><mo>.</mo><msqrt><mn>1600</mn></msqrt><mo>.</mo></math></p> <p>&nbsp;</p> <p><span style="text-decoration: underline;"><em><strong>Hướng dẫn giải:</strong></em></span></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>a</mi><mo>)</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>49</mn></msqrt><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>64</mn></msqrt><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>7</mn><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>8</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>1</mn><mo>,</mo><mn>5</mn><mo>.</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>b</mi><mo>)</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>36</mn></msqrt><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><msqrt><mn>0</mn><mo>,</mo><mn>81</mn></msqrt><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>6</mn><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>9</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mo>-</mo><mn>0</mn><mo>,</mo><mn>3</mn><mo>.</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>c</mi><mo>)</mo><mo>&#160;</mo><mn>8</mn><mo>.</mo><msqrt><mn>9</mn></msqrt><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><msqrt><mn>64</mn></msqrt><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>8</mn><mo>.</mo><mn>3</mn><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><mn>8</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>24</mn><mo>&#160;</mo><mo>-</mo><mo>&#160;</mo><mn>8</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>16</mn><mo>.</mo></math></p> <p><math xmlns="http://www.w3.org/1998/Math/MathML"><mi>d</mi><mo>)</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>.</mo><msqrt><mn>400</mn><mo>&#160;</mo></msqrt><mo>+</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>2</mn><mo>.</mo><msqrt><mn>1600</mn></msqrt><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>1</mn><mo>.</mo><mn>20</mn><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><mn>0</mn><mo>,</mo><mn>2</mn><mo>.</mo><mn>40</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>2</mn><mo>&#160;</mo><mo>+</mo><mo>&#160;</mo><mn>8</mn><mo>&#160;</mo><mo>=</mo><mo>&#160;</mo><mn>10</mn><mo>.</mo></math></p>
Xem lời giải bài tập khác cùng bài