5) \( \frac{x}{3}+\frac{x+1}{7}=\frac{x-2}{6} \)

-простіть вираз: \( \begin{array}{ll}15 \mathrm{~m}^{2} \cdot\left(4 \mathrm{~m}^{3}\right)^{2} ; & \text { 2) }-0,5 \mathrm{~m}^{5} \cdot\left(2 \mathrm{~m}^{3}\right)^{4} \\ \left.-3 \mathrm{a}^{3} \mathrm{~b}^{4}\right)^{4} \cdot\left(-\frac{1}{8} a^{3} b\right) ; & \text { 4) }\left(-\frac{4}{5} m n^{4}\right)^{3} \cdot 25 m^{4} \mathrm{n}\end{array} \)

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

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

42. Julio paid \( 7 \frac{3}{4} \% \) sales tax on an item he bought. He figured that if he had bought the item in a neighboring state where the sales tax is \( 8 \frac{1}{4} \% \), he would have paid \( \$ 75 \) more. What was the cost of the item before tax? (C) \( \$ 15,000.00 \) (IS) \( \$ 3,750.00 \) (C) \( \$ 1,500.00 \) (D) \( \$ 150.00 \) (F) \( \$ 37.50 \)

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