17,210,000,000 written in scientific notation?

Step-by-step explanation:

17,210,000,000 written in scientific notation

To write the number in scientific notation we move the decimal point after the first number.

To move the decimal point after 1, move 10 places to the left

So the number becomes

1.7210000000

Ignore all the zeros. we moved 10 places to the left so multiply with 10^10

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