(a)表达xx+4-3x-1{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分子x /分母x + 4端分数减去分子3 /分母x - 1端分数" style="vertical-align:-17px;height:47px;width:106px" loading="lazy">作为一个分数
最小公分母是x+4x-1{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="左括号x + 4右括号x - 1右括号" style="vertical-align:-6px;height:22px;width:97px" loading="lazy">
把每个分数都写在公分母上,记得把分数的上面也乘上
xx-1x+4x-1-3x+4x-1x+4{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子x开括号x减1闭括号除以分母开括号x加4闭括号开括号x减1闭括号结束分数分子3开括号x加4闭括号结束分母开括号x减1闭括号开括号x加4闭括号结束分数" style="vertical-align:-17px;height:47px;width:226px" loading="lazy">
化简分子
x2-xx+4x-1-3x+12x-1x+4{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子x²- x /分母开括号x + 4闭括号x - 1闭括号结束分数减去分数分子3x + 12 /分母开括号x - 1闭括号x + 4闭括号结束分数" style="vertical-align:-17px;height:48px;width:226px" loading="lazy">
把分数合并起来,因为它们的分母相同
x2-x-3x+12x+4x-1=x2-x-3x-12x+4x-1=x2-4x-12x+4x-1{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子x²- x -打开括号3 x + 12关闭括号在分母打开括号x + 4关闭括号打开括号x - 1关闭括号结束分数=分数分子x²- x - 3 x - 12除以分母打开括号x + 4关闭括号打开括号x - 1关闭括号结束分数=分数分子x²- 4 x - 12除以分母打开括号x + 4关闭括号,开括号,x - 1,闭括号,结束分数" style="vertical-align:-17px;height:48px;width:397px" loading="lazy">
分解顶部
x+2x-6x+4x-1{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子开括号x加2闭括号开括号x减6闭括号除以分母开括号x加4闭括号开括号x减1闭括号结束分数" style="vertical-align:-17px;height:47px;width:105px" loading="lazy">
这里没有可以约掉的项,所以这就是最终答案
(x+2)(x-6)(x+4)(x-1){"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" style="vertical-align:-17px;height:47px;width:115px" loading="lazy">
(b)表达x-42x-3-x-12x{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子(x - 4)除以分母2开括号(x - 3)结束分数减去分数分子(x - 1)除以分母2 x结束分数" style="vertical-align:-17px;height:47px;width:127px" loading="lazy">作为一个分数
最小公分母是2xx-3{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="2个开括号x - 3个闭括号" style="vertical-align:-6px;height:22px;width:68px" loading="lazy">(你也可以用4xx-3{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="4个开括号x - 3个闭括号" style="vertical-align:-6px;height:22px;width:68px" loading="lazy">但这不是最低共同点)
把每个分数都写在公分母上,记得把分数的上面也乘上
xx-42xx-3-x-1x-32xx-3{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子x开括号(x - 4)闭括号除以分母2 x开括号(x - 3)闭括号(x - 3)结束分数分子(x - 1)闭括号(x - 3)结束分数除以分母2 x开括号(x - 3)结束分数" style="vertical-align:-17px;height:47px;width:197px" loading="lazy">
化简分子
x2-4x2xx-3-x2-4x+32xx-3{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子(x²- 4x) /分母2(开括号x - 3)结束分数减去分数分子(x²- 4x + 3)除以分母2(开括号x - 3)结束分数" style="vertical-align:-17px;height:48px;width:180px" loading="lazy">
把分数合并起来,因为它们的分母相同
x2-4x-x2-4x+32xx-3=x2-4x-x2+4x-32xx-3=-32xx-3{"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="分数分子(x²- 4x -开括号x²- 4x + 3)除以分母(2 x开括号x - 3)结束分数等于分子(x²- 4x - x²+ 4 x - 3)除以分母(2 x开括号x - 3)结束分数等于分子(- 3)除以分母(2 x开括号x - 3)结束分数等于分子(- 3)除以分母(2 x开括号x - 3)结束分数等于分子(- 3)除以分母(2 x开括号x - 3)结束分数" style="vertical-align:-17px;height:48px;width:436px" loading="lazy">
没有别的东西可以分解到分子上,所以这就是最终答案
-32x(x-3){"language":"en","fontFamily":"Times New Roman","fontSize":"18","autoformat":true}" class="Wirisformula" role="math" alt="从MathML转换为可访问文本时出错。" style="vertical-align:-17px;height:47px;width:83px" loading="lazy">