Giving brainliest for CORRECT awnser.

12

Step-by-step explanation:

x^2 -bx +36

A perfect square trinomial is of the form

a^2 -2abx +b^2

x^2 -bx +6^2

a =1 and b = 6

2ab = 2*1*6 = 12

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