Determine the difference: 3.2 × 1010 – 1.1 × 1010. write your answer in scientific notation.

Step-by-step explanation:

1. Both number are written in scientific notation, because both have the following form:

Where a is a number between 1 and 10 (but not including 10) and the exponent b is an integer.

2. Both have the same exponent, therefore, you can subtract 3.2 and 1.1 and write again, as you can see below:

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