先化简,再求值[(x^2+2)⼀(x^2-3x)-(x+1)⼀(x-3)]⼀[1⼀(x-3)+1]其中x=(2⼀1)^(-1)

2024-12-22 00:50:29
推荐回答(2个)
回答1:

[(x^2+2)/(x^2-3x)-(x+1)/(x-3)]/[1/(x-3)+1]
=(x^2+2-x^2-x)/[x(x-3)]/[(1+x-3)/(x-3)]
=-(x-2)/[x(x-3)]/[(x-2)/(x-3)]
=-1/x

∵x=(2/1)^(-1)=1/2
∴原式=-1/x=-2

回答2:

Y(X) = [(x^2+2)/(x^2-3x)-(x+1)/(x-3)]/[1/(x-3)+1]
=(1+2X+2/X)/(X-2)
X=1/2 代入Y(X)
Y(1/2) = (1+1+4)/(-3/2) = -6/1.5 = -4