Answer:
Step-by-step explanation:
The slope-intercept form of an equation of a linear function:
[tex]y=mx+b[/tex]
m - slope
b - y-intercept
[tex]Equation\ 1:\ y=2x+1\qquad\boxed{YES}\\\\Equation\ 2:\ y^2=3x+1\qquad\boxed{NO}\ because\ we\ have\ y^2\\\\Equation\ 3:\ y=5x^5-1\qquad\boxed{NO}\ because\ we\ have\ x^5\\\\Equation\ 4:y=4x^4-1\qquad\boxed{NO}\ because\ we\ have\ x^4[/tex]