a) \( \frac{2 x y-1}{4 x^{3}}-\frac{3 y-x}{6 x^{2}} \);

e) \( (3 x+2) \cdot\left(x^{3}-2 x^{2}+1\right)= \)

Which of the following equations has no solution \( \begin{array}{l}x+20-5 x=7(3+x)-3 x \\ \begin{array}{l}5 x+20-7 x=7(3+x)-3 x \\ 5 x+21-x=7(3+x)-3 x \\ 5 x+20-x=7(3+x)-3 x\end{array} \\ \begin{array}{l}5\end{array}\end{array} \$ \begin{array}{l}\text { - }\end{array} \)

Question 3 A store is selling a large selection of men's shirts, and every shirt has the same price. Kiyoshi buys 6 shirts and gets a \( \$ 30 \) discount. His friend Gregory buys 4 shirts and does not receive a discount. Gregory spends \( \$ 20 \) less than Kiyoshi. What is the price of one shirt without any discount? \( \$ 25 \) \$ \( \$ 5 \) \$ \( \$ 100 \) \( \$ 80 \)

3) \( Y+\left[\begin{array}{l}-1 \\ -6\end{array}\right]=\left[\begin{array}{c}10 \\ -14\end{array}\right] \)

a) \( \log _{2} x=1-x \);