数学【人教版】五年级上方程的意义2 哈ppt课件.ppt

, :, 2- , 2 3 5 25 ., :, - ,20,30,50, - ,20 +30 =50,-,-,100+x,100+x,100g,100+x200, ,50g,100g,100g,100g,100g, ,100g,100+x,100+x300,50g, ,100g,100g,100g,50g,100+x, ,100g,100+x250,100+x,-,20,?,100,20+X=100 - ,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+50,100+2x=50 x3,X,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, , ,20+=100,50+2 180, 802, 3=180,100+2=350,20+30=50,20+=100,502=100, 3=180,100+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, : : , .,6X + =78 36 + =42,( ),( ),” .“ , . . ., , . .,2. : (1) 4.7x . ( ) (2) 0.5x=4 . ( ) (3) . ( ) (4) . ( ),X+0.5=2.5,3X=36,100,=,50,=,4 +6-3=87,+21=175,4 +6387, 30 16 . ,x 40 x x 15 100 60,X+40=100,2X+15=60, , . . x y z .,2b+15=100,5 +2+2=44,小资料,陈省身：数学有“好”数学和“不大好”的数学之分，方程，是“好”的数学的代表。, , .,2X = 50,X + 73 = 166,继续,(1) 5 9 1 x ,5x=9 95=x 9x=5,(2) 40 x 18 .,40 x=18 18x=40 4018=x, ,2050+20,2 +7=11, ,(1) X 35 91.,(2) x 3 57 .,(3) x 3 6,(4) 7.8 x 1.3.,-5+8=15,5 95, ,1. .2. X50=150、2X=200 ., 1 . ( ), :, ,20-3y=2,60 x+80=500,3y+2=20,(1) 3 . y 20 2 .,(2) 500 . 60 x 80 .,30,100,280, ,30,100 ,280, - ,100+x =280,怎样才能使两个杯子里的水一样多？,200毫升,250,甲,乙,（用方程表示,你能吗？）,甲倒掉水250-x=200,乙加水200+x =250,如果甲杯的水被倒入了乙杯又怎么列方程呢？,