Please write out the full question so we can do our best to assist you in finding the most logical answer.
Hope this helps!
The answer to your question is True.
Let S be the amount in a savings account.
Let m be the number of months.
General equation
S = 132 + 27m
Specific question
July is the 7th month of the year including both January and July.
S = 132 + 7*27
S = 132 + 189
S = 321
Reasonableness?
Good question. You could estimate an answer.
Start with 150 dollars and say that you add 25 a month.
7 * 25 = 175
S = 150 + 175 = 325 All of this was done in my head. Since the exact answer obtained using the formula is 321, I think that's pretty reasonable using my estimate is a guide.
The answer would be -7.
7 - (-4) - 18 (Simplify 3 * (-6) to -18)
7 + 4 - 18 ( Simplify brackets )
-7 (Simplify).
Because the second derivative of the function at the point is negative, the graph must be concave down at this point. Because the first derivative indicates that the function is also likely to be a maximum or minimum, the point must be a maximum.