Answer:
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Explanation:
Answer for question 3, I already gave it in the other question you made, so, here it is again:
1.56 x10^4 = 15,600
0.56x10^-2 = 0.0056
3.69x10^-2 = 0.0369
736.9x10^5 = 73690000
0.00259x10^5 = 259
0.000459x10^-1 = 0.0000459
13.69x10^-2 = 0.1369
6.9x10^4 = 69000
0.00259x10^3 = 2.59
0.0209x10^-3 = 0.0000209
Now for question 4, the easiest way to do this is to convert all the scientific notation to the same, example is one number is powered with the exponent 5, and the other has an exponent of 6, then put both powers with exponents 5 or 6, and then do the sum, or rest. If you are not allowed to use a calculator, the big numbers could be a little difficult, but we can solve it.
Now the best way for you to understand this in this exercise is the following. As all the powers exponent are positive, means that the dot will have to be runned to the right always, and when you do that, you are always one space left to the real number, for example if you have 5.678x10^6 and run the dot one space to the right you have 56.78, how many spaces you have left to write the complete number? if innitially we have 6, and you run one, means that you only have left 5 spaces, so the power exponent would be 56.78x10^5. You can also do this, to the left but instead of taking out spaces, you will add spaces.
Now for the questions, this would be the correct answers:
a) 4.53x10^5 + 2.2x10^6
Let put the powers in exponent of 5. 2.2 let's run the dot one space to the right. It would be 22.0 so, the power would be 22x10^5. Now let's do the sum of 22 + 4.53 = 26.53x10^5. You can also put it as 2.653x10^6
b) 1913.0 - 4.6x10^3 = 1.913x10^3 - 4.6x10^3 = -2.687x10^3
c) 2.34x10^24 + 1.92x10^23 = 23.4x10^23 + 1.92x10^23 = 25.32x10^23 or 2.532x10^24
d) 2.130x10^3 - 6.6x10^2 = 21.30x10^2 - 6.6x10^2 = 14.7x10^2 or 1,47x10^3