\[ f(x)=x^{2}-1 \quad g(x)=-k x^{2}+1 \quad h(x)=k x^{2}+k \] di \( \mathbb{R}_{\leqslant 2}[x] \) e sia \( B \) il sottospazio da essi generato. (i) Per quali valori di \( k \) i polinomi \( f(x), g(x) \) e \( h(x) \) sono una base di \( B \) ? (ix Calcolare la dimensione di \( B \) al variare di \( k \in \mathbb{R} \). (idi) Per quali valori di \( k \) il polinomio \( a(x)=2-k x+k x^{2} \) appartiene a \( B \) ?

Solve the following .... Gramer's rule. \( \begin{array}{c}x+2 y+3 z=6 \\ 2 x+4 y+z=7 \\ 3 x+2 y+9 z=14\end{array} \)

B) \( x+y \) \( \begin{array}{lll}\text { Ifodani soddalashtiring: } & \text { C) } x-y & \text { D) } 0\end{array} \) \( \begin{array}{lll}\text { 6) Tenglamani yeching: } \sqrt[4]{625 x}+\sqrt[4]{16 x}-\sqrt[4]{81 x}=12 & \\ \text { B) } 27 & \text { C) } 81 & \text { D) } \frac{1}{81}\end{array} \) \( \begin{array}{lll}\text { 2,6) } a-b \text { ayirma } a \text { dan katta bo' lsa, quyidagilaming qaysi biri to } g^{\prime} \text { ri bo } \\ \text { B) } b>0 & \text { C) } b=0 & \\ \text { - } b \text { ayirma } a \text { dan katta bo' la olmaydi } & \end{array} \)

समीकरण \( y=2 x \) को \( a x+b y+c=0 \) के रूप में लिखो। Write the equation \( y=2 x \) in the form of \( a x+b y+c=0 \).

187. Julie went to the post office and bought both \( \$ 0.41 \) stamps and \( \$ 0.26 \) postcards. She spent \( \$ 51.40 \). The number of stamps was 20 more than twice the number of postcards. How many of each did she buy? 188. Jason went to the post office and bought both \( \$ 0.41 \) stamps and \( \$ 0.26 \) postcards and spent \( \$ 10.28 \). The number of stamps was four more than twice the number of postcards. How many of each did he buy? 189. Maria spent \( \$ 12.50 \) at the post office. She bought three times as many \( \$ 0.41 \) stamps as \( \$ 0.02 \) stamps. How many of each did she buy?

a) \( 2 x \geq-9 \)