Q 6. Solve the inequality \[ \frac{x^{2}(x+2)}{(x+2)(x+1)} \leq 0 \]

QUESTION 12 If \( 2^{x} 5^{y}=16 \times 125 \), where \( x \) and \( y \) are positive integers, determine \( x-y \) :

Simplify he following fully: \( \frac{3^{3+1}-3^{-1}}{23^{x}} \) \( \frac{3^{x} \cdot 3^{1}-3^{x} \cdot 3^{-1}}{2 \cdot 3^{x}} \frac{3^{x}\left(1-\frac{1}{3}\right)}{23^{x}} \)

15 It is given that \( t=\frac{b^{2}-4}{3-b^{2}} \). Express \( b \) in terms of \( t \)

\( f(x)=5 x+6 ; g(x)=3 x-2 \) (h) Find \( \left(\frac{1}{g}\right)(1) \).

Câu 01: (a) Cho hàm số \( f(x)=a x^{2}-\sqrt{2} \). Tìm \( a \) biết rằng \( (f \circ f)(\sqrt{2})=-\sqrt{2} \). (b) Tìm \( m \) để hàm số \( y=\sqrt{2 x-3 m+4}-\frac{x-m}{x+m-1} \) xác định với mọi \( x>0 \).