Select linear or nonlinear to correctly classify each function.

function.

(y - 4 = -8 (x - 1) a or b

(y = x to the 4th power) a or b

(y - x to the 2nd power = 4.5) a or b

(3x + 5y = 15) a or b

a) linear

b) non-linear

1) y-4 = -8(x-1)
    y-4 = -8x+8
    y = 12-8x 
    It's Linear

2) y= x⁴
    It's non-linear

3)y-x² = 4.5
   y = 4.5+x²
   It's non-linear

4)3x+5y=15
   3x=15-5y
   It's Linear.

So, Among your all parts of the question, 
 Linear equations are:          1st & 4th
 Non-Linear equations are:  2nd & 3rd

Hope this helps!