(-9x^2 - 2x) - (-9x^2 - 3x)

Step-by-step explanation:

-9x^2-2x+9x^2+3x

-9x^2+9x^2-2x+3x

-2x+3x

=x

1.4

2.3

step-by-step explanation:

the formula for the constant of variation is

y= kx

divide each side by x

y/x =kx/x

y/x =k

we know a and y

1.   y/x = k

4/1 =4

check the other values to make sure they are the same

8/2 = 4   12/3 =4   and 16/4 =4  

the constant of variation is 4

2.   y/x = k

3/1 =3

check the other values to make sure they are the same

6/2 = 3   9/3 =3   and 12/4 =3  

the constant of variation is 3

(a) the volume of the cone is 20/3 in3

hence, option a is correct.