求m²/（m-n）-m²/（m+n）+n²/（m²-n²）的值,已知m/n=5/3,

Question

求m²/（m-n）-m²/（m+n）+n²/（m²-n²）的值,已知m/n=5/3,

Answer 1

令m=5a n=3a
则原式=25a^2/(5a-3a)-25a^2/(5a+3a)+9a^2/(25a^2-9a^2)=175a/8+9/16
再将m=5a代回去
原式=35m/8+9/16