Solve for x. 12x=20
140
110
10
40

D. 40

Step-by-step explanation:

We have been given an equation . We are asked to solve our given equation for x.

Let us solve for x using opposite operations.

Therefore, the value of x is 40 and option D is the correct choice.

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

m∠a is 90°

m∠b is 40°