Question

giúp mình gấp ạ

Answer 1

Bài 5 :

a) \(7-\left(2x+4\right)=-\left(x+4\right)\)

\(\Leftrightarrow7-2x-4=-x-4\)

\(\Leftrightarrow7-4+4=-x+2x\)

\(\Leftrightarrow7x\)

Answer 2

a: \(\Leftrightarrow x^2+x+1+2x^2-5=4x-4\)

\(\Leftrightarrow3x^2-3x=0\)

=>x=0

b: \(\Leftrightarrow\dfrac{15x}{\left(x+4\right)\left(x-1\right)}-1=\dfrac{12}{x+4}+\dfrac{4}{x-1}\)

\(\Leftrightarrow15x-x^2-3x+4=12x-12+4x+16\)

\(\Leftrightarrow-x^2+12x+4-12x-4x-4=0\)

=>-x(x+4)=0

=>x=0