新北師大版四年級(jí)數(shù)學(xué)下冊(cè)解方程練習(xí)

新北師大版四年級(jí)數(shù)學(xué)下冊(cè)解方程練習(xí)

Tosolveanequation,payattentiontothefollowing:1.Writedownthesolution.2.Aligntheequalsign.3.Usethepropertiesoftheequationtoadd,subtract,multiply,ordividethesamenumberonbothsidesoftheequation(exceptwhendividingbyzero).4.Verifythesolution.Note:Nowadays,equationsaresolvedusingequationpropertiesratherthanusingtherelationshipbetweenthefourarithmeticoperationsasinthepast.Also,thetextbookwillnotincludeequationswithunknownsinthepositionofasubtractorordivisor,suchas12-X=7and30/X=5.I.Equationswithadditionandsubtractionrelationships:X+8=24,13+X=35,X-16=42,Y-1.5=3.7,4.6+X=5.1,XII.Equationswithmultiplicationanddivisionrelationships:5X=30,7X=63,X,X/1.3=3.2,10X=72,XIII.Equationswithaddition,subtraction,multiplication,anddivisionrelationships:3X/6=51,10X-6=42,4X/2=-1.5,X/4=16,X/3.48=15.04,X+18=58,X-2.3=3.7IV.Equationswithtwounknowns:6X+X=56,4X+2X=48,9X-3X=36,8X-X=49,6X+3X=81,13.3X-3.3X=13.5V.Othertypesofequations:Type1:Somepartsoftheequationcanbecalculateddirectly.5X+25×6=305,14×2+2X=60,2X3X-0.5=2.5×13,18X+4×9=36,10XType2:Equationswithbrackets.2X×(5+1)=60,100X/(6.78×50)=7.5,3X23×(X-4.5)=69,3×(X+2)=66,10Exercise1:I.Concepts:1.Fillintheblanks.(1)XiaoMingisayearsold.Hismotherisfivetimeshisage.Hismotheris___yearsold.(2)IfX=3,whatisthevalueof2X+5?(3)If3X-1=8,whatisthevalueofX?(4)If2X+3=7X-1,whatisthevalueofX?(5)If5X+2=32,whatisthevalueofX?(6)IfX/2=4,whatisthevalueofX?(7)If3X+2=11,whatisthevalueofX?(8)If4X-5=11,whatisthevalueofX?(9)IfX/3=5,whatisthevalueofX?(10)If2X-4=10,whatisthevalueofX?II.Calculation:1.Solvethefollowingequations:(1)X+3=7(2)2X-5=11(3)3X+2=14(4)4X-3=13(5)5X+4=292.Solvethefollowingequationswithbrackets:(1)2(X+3)=16(2)3(2X-1)=21(3)4(3X+2)=323.Solvethefollowingequationswithfractions:(1)X/2+1/3=5/6(2)2X/3-1/4=1/6(3)3X/4+1/2=7/81.一個(gè)長(zhǎng)方形的長(zhǎng)為a，寬為5厘米，面積為5a平方厘米。2.判斷：方程都是等式，等式都是方程。(X)3.只列式不計(jì)算：9x=5.2x+9.525×4=100-0.45=0.345-3=12X=27/(X-8.7)4.解方程：X=31X=12X=9X=8.4X=6X=85.應(yīng)用題：(1)糧店有面粉25噸。(2)速度為700km/h。6.概念：1.(1)周長(zhǎng)為2a+2b。(2)頭的長(zhǎng)度約為y/9米。2.判斷：循環(huán)小數(shù)不一定比1大。(X)3.只列式不計(jì)算：0.35(X-5)=7.65二、解方程：X=15.45X=77.23X=1.7X=-8X=1.5X=0.25.應(yīng)用題：(1)姐姐有135張郵票，弟弟有45張郵票。(2)速度為350km/h。7.概念：1.(1)一支鋼筆的價(jià)錢為8a-0.4元。(2)長(zhǎng)為a-10厘米。(3)180-2a度。(4)S/2千米。2.判斷：方程的兩邊都加上或減去同一個(gè)數(shù)，方程依然成立。(√)方程的兩邊都乘以或除以同一個(gè)數(shù)，方程依然成立。(√)3.只列式不計(jì)算：(1)9x-10=91(2)54=3x+6二、解方程：X=11X=20方程練習(xí)4一、概念1、填空。（1）小明的身高是a米，爸爸的身高是小明身高的2倍矮0.75米。爸爸的身高是(a×2-0.75)米。（2）一個(gè)等邊三角形的一條邊是m厘米，這個(gè)等邊三角形的周長(zhǎng)是(3m)厘米。2、判斷。（1）x+x+x=x。錯(cuò)誤。（2）一輛汽車12小時(shí)行駛了t千米，每小時(shí)行駛12÷t千米。正確。二、解方程。7y+7=14解：7y=7，y=1。17x-7x=5解：10x=5，x=0.5。2.3m-0.3m=1.4解：2m=1.4，m=0.7。45-3x=15解：-3x=-30，x=10。y÷3=4解：y=12。三、列方程解應(yīng)用題。（1）糧店有大米36噸，比面粉的7倍還多1噸，糧店有面粉多少噸？卡車共運(yùn)75噸。解：設(shè)面粉的重量為x噸，則有36=