Let \( A=\left[\begin{array}{ccc}-2 & 0 & 1 \\ 2 y & x+y & -4\end{array}\right] \) and \( B=\left[\begin{array}{cc}1 & -y \\ 0 & 3 \\ 2-x & 2\end{array}\right] \) that \( A+2 B^{-1}=0 \) then what is e value of \( y \)

\( \frac { 1 } { r } \times \frac { 1 - ( \frac { 1 } { r } ) ^ { n } } { 1 - \frac { 1 } { r } } \geq \frac { 9 r } { 100 } \Rightarrow 1 - \frac { 1 } { r ^ { n } } \geq \frac { 9 r } { 100 } \)

\( f(x)=2 x-1 \) and \( g(x)=3 x^{2} \) Find both \( f \circ g \) and \( g \circ f \), stating domain and range of each.

(c) Subtract: \( 31(1-4 m+5 n) \) from \( 4 I(10 n-3 m+21) \) (d) Subtract: \( 3 a(a+b+c)-2 b(a-b+c) \) from \( 4 c(-a+b+c \)

Which is an equivalent expression for \( \left(3^{2} \cdot 5^{4}\right)^{3} ? \) \( 3^{2} \cdot 5^{12} \) \( 3^{5} \cdot 5^{7} \) \( 3^{6} \cdot 5^{12} \) \( 15^{18} \)

3. ( 0,5 điểm) Tìm \( x \) biết: \( x^{2}(x-1)+4=4 x \)