The table below lists the masses and volumes of several pieces of the same type of metal. there is a proportional relationship between the mass and the volume of the pieces of metal.

Given the table below which lists the masses and volumes of several pieces of the same type of metal.

From the table the ratio of the mass to the volume of the metal of mass 34.932 is 34.932 / 4.1 = 8.52
the ratio of the mass to the volume of the metal of mass 47.712 is 47.712 / 5.6 = 8.52
the ratio of the mass to the volume of the metal of mass 61.344 is 61.344 / 7.2 = 8.52
the ratio of the mass to the volume of the metal of mass 99.684 is 99.684 / 11.7 = 8.52

MASS (grams)            VOLUME (cubic cm.)
34.932                               4.1
47.712                              5.6
61.344                              7.2
99.684                              11.7

Since the ratio of the various masses to the volume of the metals is the same, so there is a relationship between the mass and the volume of the piece of metal.

If the volume of a piece of metal is 15.3 cubic cm, then the mass of the metal is given by 15.3 * 8.52 = 130.356 grams.

1.17+3.99a. you combine the terms with a to create 3.99 and the 1.17 stays because it has no like terms or a variable