The total mass of a textbook and 8 notebooks is 800 grams. The mass of the textbook is 200 grams. If the notebooks have the same mass, find the mass of each notebook.

Diberikan polinomial \( P(x)=x^{3}-5 x^{2}+4 x+4 \) \( Q(x)=-x^{2}-7 x+9 \) Nilai dari \( P(x)-Q(x)=\cdots \) A. \( \quad x^{3}-6 x^{2}-3 x+13 \) B. \( x^{3}-6 x^{2}-2 x+13 \) C. \( x^{3}+6 x^{2}-3 x+13 \) D. \( x^{3}+6 x^{2}-2 x+13 \) E. \( \quad x^{3}+6 x^{2}+3 x+13 \)

10. a. Show that the roots of the equation \( 2\left(a^{2}+b^{2}\right) x^{2}+2(a+b) x+1=0 \) can never be real unless \( a=b \). b. Prove that the roots of the equation \( x^{2}+(2 k-1) x+k^{2}=0 \) are real roots if \( k \leq \frac{1}{4} \).

27. Dada la matriz \( A=\left[\begin{array}{cc}a & b \\ -b & a\end{array}\right] \) [video guia: https://voutu.be/m580)hu2MnIPsi=t|Gfe9fJKvVSr7KH] a. Determine valores propios y los vectores propios complejos asociados b. Encuentre los valores caracteristicos de la matriz \( B=A^{T} A \) c. Si los valores caracteristicos de \( \left[\begin{array}{ll}a & b \\ 0 & d\end{array}\right] \) son 0 y 1 , halle los posibles valores de \( a \) y \( d \)

Determina la función usan \( f(x)=\frac{7 x-3}{2} \) - Resuelue la

2 - Qual é o valor de \( x \) \( \begin{array}{ll}\text { a) } 2^{x}=32 & \text { b) } 5^{a}=25\end{array} \)