Use the elimination method to solve the following system of equations. \( \begin{aligned} x+y=1 \\ x+y=-4\end{aligned} \) Select the correct choice below and, if necessary, fill in the answer box to complete your choice. A. The system has a single solution. The solution set is \( \} \). Type an ordered pair, using integers or fractions.) B. There are infinitely many solutions. The solution set is \( \{(x, y) \square\} \). (Type an equation. Type your answer in standard form.) C. The solution set is the empty set.

Building \( A \) is 150 feet shorter than Building B. The total height of the two buildings is 1490 feet. Find the height of each building. What is the height of Building \( A \) ? \( \square \mathrm{ft} \) (Simplify your answer. Type an integer or a decimal.) What is the height of Building B? \( \square \mathrm{ft} \) (Simplify your answer. Type an integer or a decimal.)

If \( 10^{\log x}=10^{18} \), what is the value of \( x ? \) (1 point) 18 \( 10^{18} \) -18 \( 10^{-18} \)

Find the slope and \( y \)-intercept of the graph of the equation. \[ y=\frac{2}{5} x-1 \] Slope \( =\square \) (Enter a fully reduced fraction.) The y-intercept is \( \square \). (Simplify your answer. Type an ordered pair.)

A line that includes the points \( (-8, v) \) and \( (-6,-10) \) has a slope of -8 . What is the value of \( v \) ?

1) \( y=3 x^{2}-2 x-1 \)