Given that the \( k^{\text {th }} \) term in the expansion of \( (a+b)^{n} \) is given by \( T_{k}=\binom{n}{r} a^{r} b^{n-r} \), Find the value of \( r \) for the term independent of \( x \) in the expansion of \( \left(x^{2}-\frac{1}{2 x}\right)^{21} \),

\( \log _ { 2 } ^ { 2 } x - 15 \log _ { 5 } x - 4 \leq 0 \)

d) \( \begin{aligned} \frac{x}{2}-y & =\frac{5}{2} \\ 3 x+2 y & =-1(2)\end{aligned} \)

268. Решите уравнение: \( \begin{array}{l}\text { a) }(y+2)\left(y^{2}-2 y+4\right)-y(y-3)(y+3)=44 \text {; } \\ \text { б) }(m-3)\left(m^{2}+3 m+9\right)-m(m+2)(m-2)=13 \\ \text { (B) }(3 a+1)\left(9 a^{2}-3 a+1\right)-3 a\left(9 a^{2}+4\right)=25 \text {; } \\ \text { (A) }(2 n-1)\left(4 n^{2}+2 n+1\right)-4 n\left(2 n^{2}-5\right)=21 \text {. }\end{array} \)

Evaluate the following function. Your answer should be an integer. \( f(x)=-3^{2 x-2} \), for \( x=3 \) Your answer is \( f(3)=\square \)

Вычислить следующие определители: а) \( \left|\begin{array}{cc}1 & -2 \\ -2 & 4\end{array}\right| \); б) \( \left|\begin{array}{ccc}1 & 2 & 0 \\ 0 & 0 & 3 \\ 5 & 0 & -1\end{array}\right| \), 2. Найти точку пересечения прямых \( l_{1}: 3 x-2 y=0 \) и \( l_{2}: y=-x+5 \). Построить прямые.