数学【人教版】五年级上 方程的意义 哈ppt课件.ppt
, - 5- , , : 2- , ,(1) X 50 ,(2) x ,(3) b ,X+50,x+x,2x,b-5, , -,图1,图2,图3,图4, , , - ,20,30,50, - ,20 +30 =50,20,?,100,20+X=100 ., - ., - , 100, 100 , , X .,100+x100, ,200,300,(1)100 x200,(2)100 x300,- !,250,(1)100 x=250,100+x=250 .,50,50,50 x2=100,50,x x,50+2180,80,X X ,802x,X X X ,X,50,50,50,3x=180,100+20100+30,100+2x=50 x3,20+30=50 802 20+=100 3=180502=100 100+20100+5050+2 180 100+2=350,: .,20+=100 20+30=50 50+2 180 502=100 802 100+20100+50 3=180100+2=350, , , 20+30=50 50+2 180 20+=100 802 502=100 100+20100+50 3=180100+2=350, , ,: ., ., 35- =12 ( ) 0.49 =7 ( ) Y+24 ( ) 35+65=100 ( ) 5 +32=47 ( ) -14 72 ( ) 28 16+14 ( ) 9b-3=60 ( ) 6(a+2)=42 ( ) +y=70 ( ),9,10,: ,X,X,X,X, ” “ ” “ ,x24=120 5x32=47 4.30.1=43 2x=03x8 8.5x x20=78 6(a2)=42281614, , ,4+3x=10,6+2x,7-x3,17- 8=9,8x=0,18x=2,100+2x503,802x,100+20100+50,50+2x100,50+x=100,100-20=80,20+30=50,0.49x=7,35+65=100,9b3=60,35x=45,5x+32=47,x+5=18,x3=9,3x+7=22,5(x-2)=15,x+y=9,x+79,2+7=9,x+32, ,x+x+x=15,20+30=50 100+20=12020+=100 3=180502=100 6(a+2)=1850+2 180 100+2=350,: ,x+5=18,x3=9,3x+7=22,5(x-2)=15,x+y=9,x+79,2+7=9,x+32, ,x+x+x=15,82-2=80,x-y9,2.54=10,x+5=18,2+7=9,x3=9,3x+7=22,x+x+x=15,5(x-2)=15,x+y=9,82-2=80,2.54=10,x+5=18,x3=9,3x+7=22,x+x+x=15,5(x-2)=15,x+y=9, .,6X + =78(1),(2) 42 = + 36,( ),( ), . + X 40 X = 80 3 = 24, :,20+30=50 20+=10020+=100 502=100 502=100 3=180 100+20=120 6(a+2)=18 3=180 100+2=3506(a+2)=18100+2=350, . . , , . . ., , . .,: y=0, : . .,2. : (1) 4.7x . ( ) (2) 0.5x=4 . ( ) (3) . ( ) (4) . ( ),1. . ( )2. . ( )3. . ( ) 4. 30 . ( )5. 420 . ( ) 6. x=3 . ) ),X,X,X, :,2. ( ),4. . ( ),1 . ( ),3. 3= 1.5 ( ), . ( ) 842X, , - 5- ,1. , , .,1.,2. . . ., ,(1)4+3X=10 ( ) (2)18Y=2 ( ) (3)3 X+2 X=15 ( ) (4)6+2 X ( ) (5)480=2 X-60 ( ) (6)17-8+9 ( ) (7)183=X ( ) (8)8 X+4y=1 ( ) (9)a+b=10 ( ) (10)8 X=0 ( ),x,x, X . . ., , .,2X = 50,X + 73 = 166,继续, .,X + 91 = 316,2X+200 = 2000,X,X,200,2000, , X 78 .,X,X元,X元,186,3x=186,1. ,克,克,4 +6-3=87,+21=175,4 +6387,:,2b+15=100,5 +2+2=44,x 40 x x x 60 60, .,请你用方程表示下面的数量关系。, ,(1) X 35 91.,(2) x 3 57,(3) x 3 6,(4) 7.8 x 1.3., x 5 8 22 .,x58=22, ,5x=9 95=x 9x=5,(2) 40 x 18 .,40 x=18 18x=40 4018=x,(3) A B S 42 A B 12 .,S=4212 S42=12 S12=42,(4) 5.1 x 4.75 .,5.1=x4.75 5.1x=4.75 5.14.75=x,(5) 80 . a 45.5 .,80a=45.4 45.480=a 45.4a=80,(1) 5 9 1 x , , . . x y z ., ,8 2 120 4 3 , 260 300 ( ),?,260+ x =300- x,5- 4- 86 5- 52 . ( ), ,(1)5x1=11 (2)83=5(3)6x (4)3x1545(5)23b=4 (6)18x=36, , ., , . ., , , ! !,! !,