Answer:
![3x_1+5x_2=-2\\6x_1+7x_2=-1](https://img.qammunity.org/2020/formulas/mathematics/college/bkehey19rrz3918mswwzs5bfrqkr3t1u4b.png)
The augmented matrix associated to the linear system is
![\left[\begin{array}{ccc}3&5&-2\\6&7&-1\end{array}\right]](https://img.qammunity.org/2020/formulas/mathematics/college/pi6t9esx3h8t96eu7xypjucx6fq18m9xra.png)
Using row operations we reduce the system to echelon form:
1. We substract to the second row three times the first row and obtain the matrix
that is the echelon form of the system.
Now we use backward substitution to find the solution.
1.
![-3x_2=3\\x_2=-1](https://img.qammunity.org/2020/formulas/mathematics/college/ceplq64cj2rlzzv4iqf63nj0x33u5zk0rm.png)
2.
![3x_1+5x_2=-2\\3x_1+5(-1)=-2\\x_1=1](https://img.qammunity.org/2020/formulas/mathematics/college/89qbgy5k78k7vw3x8it9i6iriq1ld81yib.png)
The the unique solution is
![(x_1,x_2)=(1,-1)](https://img.qammunity.org/2020/formulas/mathematics/college/nbvjy7va1c32h6xsxsv8pavmtbm7to97i2.png)