a²-b²
=(3/4)²-(4/3)²
=9/16-16/9
=81/144-256/144
= -175/144
于是
原式
=( -175/144)²-( -175/144)
=30625/20736+175/144
=30625/20736+25200/20736
=55825/20736
a²-b²
=(3/4)²-(4/3)²
=9/16-16/9
=81/144-256/144
= -175/144
于是
原式
=( -175/144)²-( -175/144)
=30625/20736+175/144
=30625/20736+25200/20736
=55825/20736