Which equation does NOT represent a proportional relationship between two variables with the constant of proportinality of? 1/2 A Y=X+1/2 B Y=1/2X C Y=3/6X D Y=0.5X

(D)

Step-by-step explanation:

Two variables x and y are proportionally related  if they can be written in the form y=kx, where k is the constant of proportionality.

From the given options, if

(B) is of the form y=kx

(C) is of the form y=kx with as in its lowest form.

(C) is of the form y=kx with as in fractional form.

On the Contrary,

In Option D, does not represent a proportional relationship between x and y. The constant of proportion is supposed to be a product of x.

the largest number of the four options is 1.8 x 10-2

you have it in scientific notation.

1.80 x 10-6   = 0.00000180

1.80 x 10-4   = 0.000180 (bigger, or "less small", than the former one)

so

1.8 x 10-2       = 0.0180. as you see. the "less small", or the biggest one of them all.

as you have negative exponent, it means you are dividing 1.8 by 100 (i.e. moving the dot towards left, two times).

if you had positive exponent for the scientific notation, power of tenths, you would be multiplying times 100 (moving the dot towards right) as below:

1.8 x (10)2 = 180

so. if you have negative exponent in scientific notation, move the dot toward left. if it is positive, toward right as many times the exponent tells you.