Determine whether the relation is a function or not. (-2-8). (-1.-4), (1,4),(2,8), (3, 12) function not a function​

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?

Express -5 2/5 as an improper fraction.

Travis and paula went to lunch.travis ordered a sandwich for $7.50 and paula ordered a burger for $5.25.after lunch,they left a 15% tip for the waiter.how many money did they spend altogether?