x分之x的平方-1乘以(x-1分之2x+x+1分之x)化简后,再从1,2,3三个数中选择有意义的x值带入x分之x的平方-1乘以(x-1分之2x＋x/x+1)化简后,再从1,2,3三个数中选择有意义的x值带入

Question

x分之x的平方-1乘以(x-1分之2x + x+1分之x) 化简后,再从1,2,3三个数中选择有意义的x值带入
x分之x的平方-1乘以(x-1分之2x ＋ x/x+1)
化简后,再从1,2,3三个数中选择有意义的x值带入

Answer 1

[(x²-1)/x]*[2x/(x-1)+x/(x+1)]=[(x+1)(x-1)/x]*[2x(x+1)/(x+1)(x-1)+x(x-1)/(x+1)(x-1)]=[(x+1)(x-1)/x]*[x(3x+1)/(x+1)(x-1)]=3x+1当x=2时,原式=6+1=7；当x=3时,原式=9+1=10