【2018年秋季課程人教版初一數(shù)學(xué)】整式的加減 教案

適用學(xué)科適用區(qū)域知識(shí)點(diǎn)適用年級(jí)課時(shí)時(shí)長(zhǎng)（分鐘）教學(xué)目標(biāo)教學(xué)重點(diǎn),,,.,;理;教學(xué)難點(diǎn),第1頁(yè)一、導(dǎo)入3=3=2=325，2xyxy27xy3xy74，mn2，2a，，，9，3，0，，mn2。22mn2a29?二、知識(shí)講解考點(diǎn)1同類項(xiàng)2合并同類項(xiàng)（第2頁(yè)考點(diǎn)4求代數(shù)式的值三、例題精析類型一同類項(xiàng)例題112）3x2y15y2x3）3xy2xyxyyx2222233x2x253和；y和y；1和213xyyx2xy2和2；2和xy232.例題232abab2n3m,n212與mm4mn5第3頁(yè)21355m類型二合并同類項(xiàng)例題1mnmnmn);26mn22abab2;)2222)ab3ab2ba222;ab45mn2;a2b;.22)226mn22abab2ab)222222)ab3ab2ba4ab2222...例題2531x?1.20.6x1.2x33類型三整式加減例題1a(2ab)5a2abab例題2】(1)(2x3y7)(6x5y2)第4頁(yè)類型四求代數(shù)式的值例題13x8xx12x3x12323x22x9x8x1=32當(dāng)x2時(shí)2292821=32例題2，n，m、n22．22x-2x-1=0n是則mn2222第5頁(yè)m四、課堂運(yùn)用基礎(chǔ)77xyxy若4與5,abab93x2x12x3x5()22.x25x6.x25x4.x2x4x2x6.4x2xy9y2x3xyyx2,y5:22225,4abA2xxy10y=22當(dāng)5時(shí)xy2225105=22鞏固1xy與3xy求ababa12312xy4ab4465,b,ab33與2cab在xy()組2與2,2與2,33,253組組組51152:ab3ab2abababba2232263363a2,b0ab2,a1a2,b0C11ba3ba2632第6頁(yè)拔高5ab0.9ab,y．若2與3xy:xn0.5x0.2xx0.3xn1nn1n1．22x3,y2xy2x3,y20.8x0.2xnn1）22222，．2六、課后作業(yè)基礎(chǔ)已知單項(xiàng)式3xy4x3是同類項(xiàng)，則下列單項(xiàng)式，與它們屬于同類項(xiàng)的是（）第7頁(yè)yyxyya4b4a4若b與是同類項(xiàng),求的值．．3nm2003mmna1a)0b5a615ab22222A120033得m=1,n=2nmmn1ma1，(2ab)2，a10,2ab0ab2a1a)02鞏固x3x10x5x5x8＝；2322aa4221aa.23122求,n9am2b5mn與ab2351a+b20，Aa6abb,Ba5求2AB22213,n=-5212251,5m22;mn352a1+b2ab∴AB4622510222拔高5ab與0.9ab23x,y.,求xy5xyyx2yx3xyxy:2232abababbab34ab0a3243223第8頁(yè)