Which number is not in scientific notation? URGENT! BRAINLIEST WILL BE GIVEN 1) 11 . 10^21
2) 5.7 . 10^9
3) 3.1 . 10^-12
4) 1.67 . 10^-5

1) 11 x 10^21

Step-by-step explanation:

Scientific notation must be in the form

a  x 10^b

Where a is an number between 1 and 10

Clearly the 1st one is above 10 so it goes against the rule of scientific notation

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3

the answer is:

the correct option:

b.

to solve the problem, we need to remember how to operate to simplify exponential expressions using the logarithms.

we are given the equation:

then, using placing logarith with base 7 on both sides of the equation, we have:

so, rounding the obtained result to two decimal places (nearest hundreth), we have:

hence, we have that the correct option:

b.

have a nice day!