John opens a savings account with an initial deposit of $2000. He deposits $35 each week. Mary's savings account is represented
by the function y = $45x + $2800 , where y is the balance of Mary's savings account after her initial deposit and a number of weekly deposits, x. Which statement BEST compares the rate of change for the two accounts? A) Mary deposited $800 less than John. B) John deposits $10 more each week than Mary. C) John deposits $10 less each week than Mary. D) Mary deposits $7 for every $9 John deposits.
The statement that best compares the rate of change for the two accounts is:
C) <u>John deposits $10 less each week than Mary</u>.
Step-by-step explanation:
In the equation that determines Mary's savings account balance:
y = $ 45x + $ 2800
It can be identified that the $ 2800 mentioned is the initial deposit with which the savings account was opened, so the value of $ 45 is the weekly moment that Mary saves week after week, which will be increased once the variable X increase, considering that John's weekly savings amount is $ 35, it is valid to state that John saves $ 10 less than Mary since:
$ 45 (amount saved by Mary) - $ 35 (Amount saved by John) = $ 10.
John’s savings account equation would be y=35x + 2000 while Mary’s is y=45x + 2800. By comparing them, we see that Mary deposits 10 more than John per week.
x = -9 would be the slope because when you see the two points for each coordinate there is no x value but we do see a straight line and we see that there is no y-intercept. So, x= -9 would be the answer. Hope this helps.
