如何证明a/c=b/d=(a-b)/(c-d)
来源:学生作业帮助网 编辑:作业帮 时间:2024/07/27 14:20:53
![如何证明a/c=b/d=(a-b)/(c-d)](/uploads/image/z/2693049-33-9.jpg?t=%E5%A6%82%E4%BD%95%E8%AF%81%E6%98%8Ea%2Fc%3Db%2Fd%3D%28a-b%29%2F%28c-d%29)
xݑMJ@ů
2DnD"X(ĝV]ˈ)
&ikV[w{yyR SpxyX+W$KzpX,4}˴N\Mb5R@GVDסf]1}A%@M Bto@?>#ZL̖jY@`L}BbA_
如何证明a/c=b/d=(a-b)/(c-d)
如何证明a/c=b/d=(a-b)/(c-d)
如何证明a/c=b/d=(a-b)/(c-d)
证明如下:
∵a/b = c/d
∴a/b +1 = c/d + 1
∴(a+b)/b = (c+d)/d
∴b/(a+b) = d/(c+d)
∴2b/(a+b) = 2d/(c+d)
∴2b/(a+b)-1 = 2d/(c+d)-1
∴{2b-(a+b)} /(a+b) = {2d-(c+d)} /(c+d)
∴(b-a) /(a+b) = (d-c) /(c+d)
∴-(b-a) /(a+b) = -(d-c) /(c+d)
∴(a-b) /(a+b) = (c-d) /(c+d)
∴(a+b)/(a-b)=(c+d)/(c-d)
通分
收起