Simplify each expression. \( \left(x^{2} y^{4}+3 x y^{4}-4 y^{2}\right)-\left(4 y^{2}+7 x^{2} y^{4}-7 x y^{4}\right)+\left(8 y^{2}-4 x^{3}\right) \) \( -6 x^{2} y^{4}+10 x y^{4}-4 x^{3} \) \( -14 x^{2} y^{4}+10 x y^{4}-4 x^{3} \)

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

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) \( \$ 37.50 \)

Find \( n \), \( 3 n-6=18 n^{2} \) A) 0.654 (B) -0.488 (C) 0.654 OR -0.488 (D) No real roots

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

(Express \( \frac{6}{7 h}-\frac{3-4 g}{14 h} \) as a single fraction in its simplest form. Ungkapkan \( \frac{6}{7 h}-\frac{3-4 g}{14 h} \) sebagai pecahan tunggal dalam bentuk termudah.