Which equation represents a linear function? (5 points)

Equation 1: y5 = 2x + 1
Equation 2: y = 3x + 1
Equation 3: y = 5x5 − 1
Equation 4: y = 4x4 − 1

Group of answer choices

1. Equation 1
2. Equation 2
3. Equation 3
4. Equation 4