Quadratic equations and inequalities

1003067804

Level: 
C
For \( x\in[4;\infty) \) choose the correct form of the equation \[ \left|-x^2+3x+4\right|=\left|-2 x^2+ 11 x - 12\right| \] that does not contain an absolute value.
\( x^2-3x-4=2x^2-11x+12 \)
\( x^2-3x-4=-2x^2+11x-12 \)
\(-x^2+3x+4=2x^2-11x+12 \)
\( -x^2+3x+4=-2x^2+11x-12 \)

1003067805

Level: 
C
For \( x\in[-3;5] \) find the solution set of the following equation. \[ \left|(x+3)(x-5)\right|=5 \]
\( \left\{ 1-\sqrt{11};1+\sqrt{11} \right\} \)
\( \left\{ 1-\sqrt{21};1+\sqrt{21} \right\} \)
\( \{ -3; 5 \} \)
\( \left\{1-\sqrt{21}; 1-\sqrt{11};1+\sqrt{11};1+\sqrt{21} \right\} \)

1003067810

Level: 
C
Find the solution set of the following equation. \[ |x-4|\cdot(x+4)=4 \]
\( \left\{-2\sqrt3;2\sqrt3;2\sqrt5\right\} \)
\( \{ -4; 4 \} \)
\( \left\{ -2\sqrt3;2\sqrt3\right\} \)
\( \left\{ 2\sqrt3;2\sqrt5\right\} \)
\( \left\{-2\sqrt5;-2\sqrt3;2\sqrt3;2\sqrt5 \right\} \)