Which of the following numbers are written in scientific notation? 0.641 x 10^3
2 x 10^1
9.999 x 10^4
4.38 x 5^10

2 x 10^1

9.999 x 10^4

Step-by-step explanation:

when using scientific notation

M x 10^X

M has to be between 1(inclusive) and 10

and has to be multiplied by ten to the power of x

2 x 10^1

9.999 x 10^4

Step-by-step explanation:

For a number to be written in Scientific Notation, it has to abide to 2 rules:

1) It has to be within 1 and 10.

2) It has to be multiplied by ten to the power of a number(x)

Ex:

1.473 x 10^7 is written in Scientific Notation

6.9 x 17^3 is not written in Scientific Notation

0.372 x 10^39 is not written in Scientific Notation

This all means that 4.38 x 5^10 and 0.641 x 10^3 are not written scientific notation, as they do not abide to all the rules of the equation to be written in Scientific Notation, meanwhile 2 x 10^1 and 9.999 x 10^4 are written in Scientific Notation, as they abide to all rules of an equation to be written in Scientific Notation.

13cm

step-by-step explanation:

(apex)