\[ \begin{aligned} x-y=5 \\ -7 x+7 y=8\end{aligned} \] Select the correct choice below and fill in any answer boxes in your choice, if necessary. A. There is one solution. The solution is (Type an ordered pair. Simplify your answer.) B. There are infinitely many solutions. The solution set is \( \{(x, y) \mid-7 x+7 y=8\} \). C. There is no solution.

Find \( x \). \( \frac{x-1}{3}=\frac{5}{x}+1 \) A. 6.36 OR -2.36 (B) 6.36 (C) 5.46 OR 2.36 (D) No real roots

expunencial \( \left.\left(4^{2}\right)\left(2^{3}\right)^{2 x-5}\right)=8 \)

f) \( (-15 a b c+12 a b-9 a c-3 a) \div(-3 a) \)

Exercice N1 \( \begin{array}{lll}\text { Simplifier les expressions suivantes puis calculer leur valeur: } \\ \begin{array}{lll}\text { 1. } a=5^{1,7} \times 5^{1,3} & \text { 2. } b=\left(2^{-\frac{1}{5}}\right)^{6} & \text { 3. } c=4^{-0,7} \times \times \frac{1}{4^{0,3}}\end{array} & \text { 4. } d=\frac{6^{4,5} \times 6^{2,3}}{\left(6^{1,6}\right)^{3}}\end{array} \)

3. At a school, \( 40 \% \) of the sikthegrade students said that hip-hop is their favorite kind of music. If 100 sixth-gade students preler hip hop music, how many sixth-grade studer are at the school? Explain or show your reasoning.