Sandra used her debit card to buy lunch for $8.74 on monday . on tuesday she deposited $8.74 back into her account. what is the overall increase or decrease in her bank account

The answer to this question would be: $0 (no increase/decrease in her bank account).

To answer this question you need to list the increase and decrease Sandra cause. The increase happened when she deposited $8.74 money on Tuesday. The decrease happened when she use $8.74 money for lunch on Monday. If you add them together, it will become
Bank account: increase-decrease
Bank account : $8.74 - $8.74= $0

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.