The perimeter of a rectangle is \( 30 \mathrm{ft} \). The length is 7 ft longer than the width. Find the dimensions. Write a system of linear equations and solve the resulting system. Let \( x \) be the length and \( y \) be the width. Write the first equation. \( 2 x+2 y=30 \) Write the second equation. \( x=y+\square \)

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

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

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.

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