人教版五年级数学上册第四单元第九课时稍复杂的方程ppt课件.ppt
,2x20180 1802x = 20 ,2x40400 2x 400= 40 ,3x825 3x 25= 8 ,2x3886 86 2x = 38 ,(1) 180 . x 2 20 - ,1. .,(2) 400 2 . X 40 ,(3) 25 .X 3 8 ,(4) 86 38 .X ,【 5-1-】 ,【 5-1-】 , 2 2.8 2.4 ,2= ( + ), + = , :,2, , 2 ., 10.4 .,2+2.82=10.4 2+5.6=10.4 2+5.6 5.6 =10.45.6 2=4.8 22=4.82 =2.4, + = , . X : , : 2.4 ., .,(+2.8)2=10.4(+2.8)22=10.42 +2.8=5.2,+2.82.8=5.22.8 =2.4,2= , : 2.4 ., ., :,5+ 1.55 = 17.5,(3 ) 2 = 8.5, ,1. :,224=11,242=11,4 11 ., 4 ., , , .,2- , :2.5,102- , :, 237 - 3 - . 38 ,3X, .,