Question

Giải các pt và bpt:

a (x+4)(\(\frac{1}{4}\)x-1)=0

b\(\frac{x+2}{x-2}\)-\(\frac{x-2}{x+2}\)=\(\frac{4}{x^2-4}\)

c 2(x-5)<_5(x+1)

Answer 1

a. (x+4)(\(\frac{1}{4}\)x-1)=0

=>[\(\begin{matrix}x+4=0\\\frac{1}{4}x-1=0\end{matrix}\)

=>[\(\begin{matrix}x=-4\\\frac{1}{4}x=1\end{matrix}\)

=>[\(\begin{matrix}x=-4\left(n\right)\\x=4\left(n\right)\end{matrix}\)

S={-4;4}

b.

⇔\(\frac{x^2+4x+4}{x^2-4}\) -\(\frac{x^2-4x+4}{x^2-4}\) =\(\frac{4}{x^2-4}\)

=>\(x^2+4x+4-x^2+4x-4-4=0\)

⇔ 8x - 4=0

⇔x=\(\frac{1}{2}\) (n)

S=\(\left\{\frac{1}{2}\right\}\)

c.

=>2x-10< 5x+5

=>-3x <15

=> x > 5 (n)

{x/x>5}