Toán Lớp 8: rút gọn:2x/1-x^3+1/x^2-x-1/x^2+x+1
Leave a reply
Register Now
Login
Lost Password
Lost your password? Please enter your email address. You will receive a link and will create a new password via email.
Toán Lớp 8: rút gọn:2x/1-x^3+1/x^2-x-1/x^2+x+1
Comments ( 1 )
Lời giải và giải thích chi tiết:
(2x)/(1-x^3)+1/(x^2 -x)-1/(x^2 +x+1) (x \ne 0;1)
=-(2x)/((x-1)(x^2 +x+1))+1/(x(x-1))-1/(x^2 +x+1)
=-(2x.x)/(x(x-1)(x^2 +x+1))+(x^2 +x+1)/(x(x-1)(x^2 +x+1))-(x(x-1))/(x(x-1)(x^2 +x+1))
=-(2x^2 +x^2 +x+1-x(x-1))/(x(x-1)(x^2 +x+1))
=-(2x^2 +x^2 +x+1-x^2 +x)/((x^2 -x)(x^2 +x+1))
=-(2x^2 +2x+1)/(x^4 +x^3 +x^2 -x^3 -x^2 -x)
=-(2x^2 +2x+1)/(x^4 -x)