用两种不同的运算顺序计算 (x-2分之x-x+2分之x)×(这是乘号) (x分之2-x)

问题描述:

用两种不同的运算顺序计算 (x-2分之x-x+2分之x)×(这是乘号) (x分之2-x)

①(x-2分之x-x+2分之x)*(x分之2-x)
=[x/(x-2)-x/(x+2)]*[-(x-2)/x]
=-1+(x-2)/(x+2)
=(-x-2+x-2)/(x+2)
=-4/(x+2)
②(x-2分之x-x+2分之x)*(x分之2-x)
=[x/(x-2)--x/(x+2)]*(x/(2-x)
=[(x²+2x-x²+2x)/(x-2)(x+2)*[-(x-2)/x]
=[4x/(x+2)(x-2)]*[-(x-2)/x]
=-4/(x+2)