Idon't know how to do "log" can someone tell me what it is and how to do it

The ratio pv to nrt is plotted against pressure for ch4 at 0°c and 200°c. why does the curve for 0°c drop below the horizontal line for an ideal gas whereas the curve for 200°c does not?

The graph and table shows the relationship between y, the number of words jean has typed for her essay and x, the number of minutes she has been typing on the computer. according to the line of best fit, about how many words will jean have typed when she completes 60 minutes of typing? 2,500 2,750 3,000 3,250

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?