Solve this nonlinear system of equations using substitution

Question

1. Use the Substitution methodto solve this system of linear equations:

4x - y = 5
-x + y = -2

2. Solve this nonlinear system of equations using Substitution.

3x² + 4x - y = 7
2x - y = -1

3. Form the augmented matrix and then use the Gauss-Jordan Elimination method to solve this linear system:

x + y + 2z = 1
-x + z = -2
2x + y + 5z = -1