A gasoline tank
is initially 2/3 full. After som travel the tank is only 1/8 full. the tank is then filled to capacity by putting in
21 gallons of gasoline How many gallons of gasoline were in the tank initially?

Ab=dc ac=de ad=bce i hope this !

the law of definite proportions states samples of a compound will always contain the same proportion of elements by mass. in other words, a given compound will always contain the same elements in the same proportions by mass.the law of multiple proportions states when two elements combine with each other to form more than one compound, then the weights of one element that combine with a fixed weight of the other are in a ratio of small whole numbers.