Question

Answer 1

giúp mình với đang gấp lắm mn ơi

 

Answer 2

15) Ta có: \(\left(x^2-2x+4\right)\left(x+2\right)-x\left(x-1\right)\left(x+1\right)+3=0\)

\(\Leftrightarrow x^3+8-x^3+x+3=0\)

hay x=-11

Answer 3

4: Ta có: \(5x\left(x-3\right)=\left(x-2\right)\left(5x-1\right)-5\)

\(\Leftrightarrow5x^2-15x-5x^2+x+10x-2+5=0\)

\(\Leftrightarrow4x=-3\)

hay \(x=-\dfrac{3}{4}\)