Solve the equation for y.

4.2x−1.4y=2.1

y=3x- 3/2

Step-by-step explanation:

4.2x−1.4y=2.1

Subtract 4.2x from each side

4.2x-4.2x−1.4y=-4.2x+2.1

-1.4y = -4.2x +2.1

divide each side by -1.4

-1.4y/-1.4y = -4.2x/ -1.4 +2.1/-1.4y

y=3x- 3/2

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional