Explanation
a linear function must have
dependent and independent variables, ( y and x in this case)and the exponent of the independent vairable must be 1, so
Step 1
Check
a)
[tex]a)\text{ y=x-1}[/tex]this is a linear function
b)
[tex]y=4.5[/tex]this is not a functin, this expression has not x
c)
[tex]3x-4y=2[/tex]this functin has x and y, and the exponent of x is 1, so, this is a linear function
d)
[tex]5x^2=10y[/tex]this function has x and y, but the exponent is 2, so this is not a linear function
e)
[tex]y=\frac{1}{2}x^2+6[/tex]this function has x and y, but the exponent is 2, so this is not a linear function
i hope this helps you