Use substitution to solve the system of equations. 5. \( \left\{\begin{array}{l}y=3 x^{2}+7 x-10 \\ y-19 x=22\end{array}\right. \)

\( A=\left[\begin{array}{ccc}1 & -2 & 0 \\ 2 & 1 & -3 \\ 0 & -2 & 1\end{array}\right] \begin{array}{c}x-2 y=10 \\ 2 x+y+3 z=8 \\ -2 y+z=7\end{array} \quad \) find \( A-1 \)

Solve \( \log _{2}\left(\log _{4} x\right)=3 \) (1 point) \[ \begin{array}{l}x=262,144 \\ x=4,096 \\ x=65,536 \\ x=6,561\end{array} \]

295 Три числа, които образуват намаляваща геометрична прогресия, имат сбор 56 . Те са първи, пети и седми член на аритме- тична прогресия. Намерете тези числа.

1) \( \lg (x-1)-\lg (2 x-11)=\lg 2 \)

The electricity rates charged by Monroe Utilities in the summer months are as follows. - Base Charge is \( \$ 8.50 \) - First 600 kWh or less at \( \$ 0.05 / \mathrm{kWh} \) - Over 600 kWh at \( \$ 0.08 / \mathrm{kWh} \) The base is a fixed monthly charge, independent of the kWh (kilowatt-hours) used during the month. a. Find an expression for the cost function \( C(x) \) for usage of or under 600 kWh . \( C(x)=\square<x \leq 600 \) b. Find the charge for using 800 kWh . \( \$ \square \)