Solve for X

Pls help

xxxtentacion=6&20

Step-by-step explanation:

12

Step-by-step explanation:

The sum of any two intieior angles in a triangle equal to the opposite angle.

So 30 + 5X + 15 = 9X - 3

Solving for X

48 = 4X

X = 12

8

step-by-step explanation:

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