Solution:
Principal =P= $ 7,500
Option A→(Simple interest)
Rate of interest= R=4%
Time(
)=4 years
Time(
)=6 years
Amount= Principal + Interest(Simple or compound interest)
Formula for Simple interest


Total amount after 4 years when interest is simple= 7500 +1200= $ 8700
Total amount after 6 years when interest is simple= 7500 +1800= $ 9300
Option B
Formula for amount(A) when interest is 3.15% compounded annually.



Total amount after 4 years when interest is compounded annually=$ 8491 (approx)
Total amount after 6 years when interest is compounded annually=$ 9034(approx)
When applying indirect proofs, we assume the negation of the conclusion is true, and show that this assumption would lead to nonsense, or contradiction.
In our case we assume a is not smaller than 7, that is we assume a≥7.
a≥7 then, multiplying both sides by 3:
3a≥21, then, adding both sides 7:
3a+7≥28,
which is a contradiction because 3a+7 is smaller than 28.
So our assumption is wrong, which means the opposite of it is correct.
Answer: assume a≥7
The correct answer is the graph in the top right corner because it is a constant function. The bottom left graph is also considered a function but is an absolute function. So both are technically correct.
Any linear equation can be written as
y = mx+b
where m is the slope and b is the y intercept
m = 1/2 in this case. It represents the idea that the snow fell at a rate of 1/2 inch per hour. In other words, the snow level went up 1/2 an inch each time an hour passed by.
b = 8 is the y intercept. It's the starting amount of snow. We start off with 8 inches of snow already.
The info "snow fell for 9 hours" doesn't appear to be relevant here.
If the line is parallel, it has the same slope. So now just find the y intercept and put it into slope-intercept form