Hi, i can't seem to answer the letter > an empty vial weighs 55.32 g. (a) if the vial weighs 185.56 g when filled with liquid mercury (d 13.53 g/cm3), what is its volume? (b) how much would the vial weigh if it were filled with water (d 0.997 g/cm3 at 25°

Subtract the mass when full from the mass when empty.
185.56 - 55.32 = 130.26 g. 
Divide by the density of liquid mercury to find the volume.
130.26 g / 13.53g/cm^3 = 9.62601626 cm, the volume of the vial.

If water was used instead of mercury, the fluid mass would be
9.62601626 cm * .997 g/cm^3 = 9.597 g

Adding this to the empty vial mass of 55.32 gives a final mass of 64.916 g.

m=9

step-by-step explanation:

7m+8=71 subtract   8 from 71 which is 63 than divide it by 7m   equal 9.