1) Aplicando o método da substituição, resolva os seguintes ...

1. Aplicando o método da substituição, resolva os seguintes sistemas $2 \times 2$ : a) $\left\{\begin{array}{l}x-y=5 \\ x+3 y=9\end{array}\right.$ b) $\left\{\begin{array}{l}3 x-2 y=6 \\ x-3 y=2\end{array}\right.$ c) $\left\{\begin{array}{l}x+y=4 \\ 2 x+y=7\end{array}\right.$
2. Aplicando o método da substituição, resolva os seguintes sistemas: a) $\left\{\begin{array}{l}x-y=1 \\ -x+2 y=3\end{array}\right.$ b) $\left\{\begin{array}{l}x=3 y \\ x-2 y=3\end{array}\right.$ c) $\left\{\begin{array}{l}2 x+y=-3 \\ x+y=-1\end{array}\right.$
3. Aplicando o método da ADIÇÃO, resolva os seguintes sistemas: a) $\left\{\begin{array}{l}x-y=3 \\ 2 x+y=9\end{array}\right.$ b) $\left\{\begin{array}{l}x=3 y \\ x+2 y=10\end{array}\right.$ c) $\left\{\begin{array}{l}x+y=10 \\ 2 x-y=8\end{array}\right.$ d) $\left\{\begin{array}{l}x=2 y \\ 3 x+5 y=55\end{array}\right.$ e) $\left\{\begin{array}{l}4 x+y=7 \\ 2 x-5 y=9\end{array}\right.$ f) $\left\{\begin{array}{l}x+y=8 \\ 4 x-6 y=12\end{array}\right.$ g) $\left\{\begin{array}{l}x-3 y=9 \\ 2 x+3 y=6\end{array}\right.$ h) $\left\{\begin{array}{l}2 x+3 y=0 \\ 3 x+5 y=2\end{array}\right.$ i) $\left\{\begin{array}{l}5 x+4 y=1 \\ 2 x-3 y=5\end{array} \quad\right.$ j) $\left\{\begin{array}{l}x-y=1 \\ x-3 y=-3\end{array}\right.$