Question

Answer 1

16: Ta có: \(x\left(x-5\right)\left(x+5\right)-\left(x+2\right)\left(x^2-2x+4\right)=17\)

\(\Leftrightarrow x\left(x^2-25\right)-x^3-8-17=0\)

\(\Leftrightarrow x^3-25x-x^3-25=0\)

\(\Leftrightarrow-25x=25\)

hay x=-1

Answer 2

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

\(\Leftrightarrow4x^2-20x-4x^2+3x+4x-3=5\)

\(\Leftrightarrow-13x=8\)

hay \(x=-\dfrac{8}{13}\)

2: Ta có: \(\left(3x-4\right)\left(x-2\right)=3x\left(x-9\right)-3\)

\(\Leftrightarrow3x^2-6x-4x+8-3x^2+27x+3=0\)

\(\Leftrightarrow17x=-11\)

hay \(x=-\dfrac{11}{17}\)