【導(dǎo)讀】程中的易錯(cuò)點(diǎn),熟練準(zhǔn)確地進(jìn)行分式的化簡(jiǎn);2x,其中x是方程x. 求代數(shù)式的值所涉及到的知識(shí)與方法:。法公式、整式運(yùn)算法則;分式的通分、元二次方程,分式方程,一元一次不。等式及不等式組的解法,整體代入等。0的根13x),其中m是方程x2m52(m6m3m3m求代數(shù)式的值22?????????互為相反數(shù)的兩式約分忘記負(fù)號(hào);············先將其中一式提負(fù)號(hào)后再約分。3.易錯(cuò)點(diǎn)及規(guī)避策略:。直接去分母或通分后去分母······················分式只能通分約分而不能去分母。除式有括號(hào)用分配律直接去括號(hào);············先算括號(hào),再做除法。括號(hào)前是負(fù)號(hào),去括號(hào)忘記變號(hào)················通分后先將各分子添上括號(hào)后寫在一。5求值得:原式,2x2-x化簡(jiǎn)得:原式-????