Question

Giúp mik với khó quá ;-;

Answer 1

Bài 1:

1: =>x(2x-5)(2x+5)=0

hay \(x\in\left\{0;\dfrac{5}{2};-\dfrac{5}{2}\right\}\)

2: \(\Leftrightarrow2x^2+8x-x-4=0\)

=>(x+4)(2x-1)=0

hay \(x\in\left\{-4;\dfrac{1}{2}\right\}\)

3: \(\Leftrightarrow x^3-x-6x-6=0\)

\(\Leftrightarrow x\left(x-1\right)\left(x+1\right)-6\left(x+1\right)=0\)

\(\Leftrightarrow\left(x+1\right)\left(x^2-x-6\right)=0\)

=>(x+1)(x-3)(x+2)=0

hay \(x\in\left\{-1;3;-2\right\}\)

4: \(\Leftrightarrow3x^2-12x-5x-3x^2=-34\)

=>-17x=-34

hay x=2

5: \(\Leftrightarrow\left(4x-3\right)\left(4x-3+3x\right)=0\)

=>(4x-3)(7x-3)=0

hay \(x\in\left\{\dfrac{3}{4};\dfrac{3}{7}\right\}\)

Answer 2

Thôi cảm ơn mình tự làm đc r :)