稍复杂的方程解决问题ppt课件.ppt

,5-1-4-,-2 47.-495,2+47-,：x，,2x+47=495,2x+47-47=495-47,2x=448,2x2=4482,x=224,:-224.,：84 4 8,：x.4 X8=84 4 X88=84+8 4 X=92 4X4=924 X=23.,:23.,84 3 15.,.：,：,：x.,.3 X15=84 3X1515=8415 3X=69 3X3=693 X=23.,84 3 15,:23.,2x20180 18020 x=20,2x40400 2x 400=40,3x825 3x 25=8,2x3886 86 2x=38.,1.,180-2 20.-x.,（2）400 2 40。x,(3)25 3 8 x.,（4）86 38.x。,2.。,3.720 2 160,4.1428 5 3,1.4X+13=365 8+4X=56 3X2=28,720 2 160.2 30.4 8 120.4 13.,2.。,.,=,x,.,+=,(+)2=,2 2.8 2.4,2,10.4,2Kg,：:,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,+=,:2.4.,:,2=,(+2.8)2=10.4(+2.8)22=10.42+2.8=5.2,.,:2.4.,+2.82.8=5.22.8=2.4,2x2.83=13.2 2x8.4=13.22x8.48.4=13.28.4 2x=4.8 x=2.4:2.4,2 3 13.2 2.8(),+=,：:,357 3 79,：X,79 3+3X=357,237+3X=357,3X=120,X=40,:40。,357,79,?,(79+X)3=357,2373X237=357237,:,5+1.55=17.5,(3)2=8.5,1.4 18 36 2.32.5 8 0.5.,1.237 3 38 2.72 20 16 2.4 3.2 4 22 2.4,(26+)3=150,！,