Question

đang gấp, giúp e với ạ

bài 1: giải các pt sau: a, 1/x-2+3=7-x/x-2

                                   b, x^2-x/x+3-x^2/x-3=7x^2-3x/9-x^2

                                   c, x/2x-1 + x+1/x+2=0

                                   d, 2/x+1 - 1/x-2 = 3x-11/(x+1)(x-2)

Answer 1

a: =>1+3x-6=7-x

=>3x-5=7-x

=>4x=12

=>x=3(nhận)

b: \(\Leftrightarrow\dfrac{x^2-x}{x+3}-\dfrac{x^2}{x-3}=\dfrac{-7x^2+3x}{\left(x-3\right)\left(x+3\right)}\)

=>\(x^3-3x^2-x^2+3x-x^3-3x^2=-7x^2+3x\)

=>\(-7x^2+3x=-7x^2+3x\)

=>0x=0(luôn đúng)

Vậy: S=R\{3;-3}

c: =>x(x+2)+(2x-1)(x+1)=0

=>2x^2+2x-x-1+x^2+2x=0

=>3x^2+3x-1=0

\(x=\dfrac{-3\pm\sqrt{21}}{6}\)

d: =>2(x-2)-x-1=3x-11

=>3x-11=2x-4-x-1=x-5

=>2x=6

=>x=3(nhận)