Question

Giải các phương trình

a)(3x-2)(2x+5)=0

b)\(\dfrac{x-1}{x+1}\)+\(\dfrac{4}{1-x^2}=\)\(\dfrac{2\left(x+1\right)}{x-1}\)

c)/X+1/+/x\(^2\)+x-2/=x\(^3\)-1

Answer 1

a)\(=>\left[{}\begin{matrix}3x-2=0\\2x+5=0\end{matrix}\right.=>\left[{}\begin{matrix}3x=2\\2x=-5\end{matrix}\right.=>\left[{}\begin{matrix}x=\dfrac{2}{3}\\x=-\dfrac{5}{2}\end{matrix}\right.\)

Answer 2

b.\(\dfrac{x-1}{x+1}+\dfrac{4}{1-x^2}=\dfrac{2\left(x+1\right)}{x-1}\)

\(ĐK:x\ne\pm1\)

\(\Leftrightarrow\dfrac{\left(x-1\right)\left(x-1\right)-4}{\left(x-1\right)\left(x+1\right)}=\dfrac{2\left(x+1\right)\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}\)

\(\Leftrightarrow\left(x-1\right)^2-4=2\left(x+1\right)^2\)

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

\(\Leftrightarrow x^2+6x+5=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-1\left(ktm\right)\\x=-5\left(tm\right)\end{matrix}\right.\)

Answer 3

=>[3x−2=02x+5=0=>[3x=22x=−5=>⎡⎢ ⎢⎣x=23x=−52