4. Дараах тэгшитгэлийн системуүдийг бод. 2. \( \left\{\begin{array}{l}7+\frac{x-3 y}{4}=2 x-\frac{y+5}{3} \\ \frac{10(x-y)-4(1-x)}{3}=y\end{array} \quad\right. \) б) \( \left\{\begin{array}{l}\frac{x+2 y}{3}-\frac{1}{5}=\frac{x+5}{15} \\ x-3 y=12,5-0,25 y\end{array}\right. \)

will be cqual, if either \( b=0 \), or \( a^{3}+b^{2}+c^{3}-3 a b c-0 \). If \( a, b, c \) arc rational and \( a+b+c=0 \), show that the roots of \( (b+c-a) x^{2}+(c+a-b) x+ \) \( (a+b-c)=0 \) are rational.

sum of partial fractions. c. \( \frac{x^{2}-3}{x^{3}+x^{2}+x+1} \)

Which is equal to \( \frac{10}{2+i} ? \) A. \( 5-10 i \) B. \( 4-2 i \) C. \( 5+\frac{10}{i} \) D. \( 4+2 i \) E. \( 5+10 i \)

3. Uis tiene el triple de dinero de maria menos \( \$ 1,0000 \) si entre ambos tienen \( \$ 110,000 \) ¿Cuanto dinero tiene en tatal maria?

\( 4 x^{2}+k x+5=0 \) has roots whose difference is \( \frac{1}{4} \)