\( 1 + 2 + 4 + \ldots . + 2 ^ { n - 1 } = 2 ^ { n } - 1 \)

Solve. \( \begin{array}{l}-3 x-5 y=5 \\ 5 x+5 y=15\end{array} \) \( (\square, \square) \) Submit

6. \( \begin{aligned} x+y+z & =0 \\ 3 x+2 y-2 z & =0 \\ 4 x+3 y-z & =0 \\ 6 x+5 y+z & =0\end{aligned} \)

1) Solve. \( \begin{array}{l}\text { y }=-4 x-3 \\ y=-5 x-6\end{array} \) \( (\square, \square) \) Submit

4. \( 184-7(2 x+5)=301+6(x-1)-6 \) 5. \( 7(18-x)-6(3-5 x)=-(7 x+9)-3(2 x+5)-12 \) 6. \( 3 x(x-3)+5(x+7)-x(x+1)-2\left(x^{2}+7\right)+4=0 \)

Simplify the polynomial, then evaluate for \( x=-3 \). \( -x^{2}+2 x-2 x^{2}-3 x+4+x^{2} \)