How do you know when to use the subtraction property of equality as a reason as opposed to subtraction of real numbers?

Tanya has $42 to spend at the dolphin island store. tshirts sell for $7 each and a pair of sunglases sells for $6.tanya buys 3 tshirts. how many pairs of sunglases can she buys with the amount of money she has left

Acredit union pays 5% annual interest, compounded daily, on saving deposits. find the value after one year of $500 deposited in this account. a-$20.40 b-$25.64 c-$520.40 d-$525.64

Pleasseee important quick note: enter your answer and show all the steps that you use to solve this problem in the space provided. use the circle graph shown below to answer the question. a pie chart labeled favorite sports to watch is divided into three portions. football represents 42 percent, baseball represents 33 percent, and soccer represents 25 percent. if 210 people said football was their favorite sport to watch, how many people were surveyed?