1.Solve by the substitution method.3x - 5y = 15

y = 2x + 4

2. Solve by the elimination method.2x - 5y = 1

3x - 4y = -2

3. Solve by the substitution method.2x + 8y = 1

x = 2y

4. Solve by the substitution method.x + y = 3

2x + 3y = -4