On dr v’s bookshelf there are 23 science textbooks each with an average of 31 chapters of each chapter contains 5 pages how many total pages are there . round answer to 2 significant figures

There are 3600 pages to 2 significant figures

Explanation:

Working only with the information given, we have that there are 23 books each with about 31 chapters.

This means that if 1 book has 31 chapter, the 23 science books will have

31 X 23 chapters =713 chapters in total.

If each chapter contains 5 pages, for the 713 chapters we will have a total of 713 X 5 pages = 3565 pages.

Rounding off the answer to 2 significant figures , we are looking to have only two non-zero figures in our answer. To do this, we count two numbers from the left. This will be numbers 3 and 5.

Next,  we check the net number after 5 to see if it is greater than 5 if it is, we will have to add the number (1 ) to the 5. This shows that we are approximating upwards, to account for the fact that that number has passed the middle point.

After this, we change the remaining two numbers (6 and 5) to zeroes.

This will give us 3600 pages.

108

explanation:

ergfywefywefdwuduweefuy

2fe + 3h2so4 -> fe2(so4)3 + 3h2

it is necessary to balance equations in order to get the proper amount of reactants as well as products in order not to make a miscalculation.

you cannot change the subscripts as that would change the substance itself. for instance, diatomic elements such as h2 only have the subscript two when a gas. another example would be so4, if you were to change the subscript, the element would no longer be sulfate.

we change the coefficients instead as that only changes the number of molecules rather than the substance itself.

hope this !