(Scientific Notation in the Real World MC)Write the expression as a number in scientific notation. 4.2 x 1010 3.4 x 1010 4.2 x 105 3.4 x 105

The question seems to be asking for the conversion of four different numbers into scientific notation. However, all four numbers are already in scientific notation.

1. 4.2 x 10^10 is already in scientific notation.
2. 3.4 x 10^10 is already in scientific notation.
3. 4.2 x 10^5 is already in scientific notation.
4. 3.4 x 10^5 is already in scientific notation.

If you meant to ask for these numbers to be written out in standard form, then:

1. 4.2 x 10^10 = 42,000,000,000
2. 3.4 x 10^10 = 34,000,000,000
3. 4.2 x 10^5 = 420,000
4. 3.4 x 10^5 = 340,000

The question seems to be asking for the sum of the four numbers, all of which are given in scientific notation. Here's how you can do it:

1. Add the numbers that have the same exponent first.

2. 4.2 x 10^10 + 3.4 x 10^10 = 7.6 x 10^10

3. Then, 4.2 x 10^5 + 3.4 x 10^5 = 7.6 x 10^5

4. Now, you have two numbers: 7.6 x 10^10 and 7.6 x 10^5.

5. These cannot be directly added because they have different exponents. They can be added if they are converted to the same exponent.

6. If we convert 7.6 x 10^5 to the exponent 10, it would be 0.0000076 x 10^10.

7. Now, add this to 7.6 x 10^10, we get 7.600000076 x 10^10.

So, the sum of 4.2 x 10^10, 3.4 x 10^10, 4.2 x 10^5, and 3.4 x 10^5 is 7.600000076 x 10^10.