Answer:
4%
Step-by-step explanation:
Since she first goes down 20% you would do 3000 times 20 which is 60000 and divided by 100 which is 600 and you would subtract 600 from 3000 which is 2400 and then you would multiply that by 30 which is 72000 and then you would divide by 100 which is 720 and add that to 2400 which is 3120 and to find the percent change from 3000 to 3120 you would subtract 3120 by 3000 which is 120 and you would divide that by 3000 which is 0.04 and multiply that by 100 which is 4 so the percent change would be 4%
To solve for the A or the principal amount plus interest you can use two formulas:
A = P + I
Where: P = Principal
I = Interest
or you can use
A = P (1+ rt)
Where: P = principal
r = rate in decimal
t = time in years
With your given you can use the second one, without having to use the first.
Given that the Principal amount is $222 and the rate is 12% and time is 10 years, we first need to convert your rate into decimal by dividing the value in percent by 100 which will yield 0.12.
Then now we can just input the data that you know into the formula:
A = P(1+ rt)
= $222(1 + (0.12)(10))
= $222(2.2)
= $488.40
Your A is then equal to $488.40
If you need to get the simple interest all you need to use is the first formula given:
A = P + I
for the interest you transpose the P to the side of the A and you will get:
I = A - P
= $488.40 - $222
= $266.40
$266.40 is the added interest to the principal amount.
Off the top of my head i can tell that B) 3 and A) -1 are two possible roots, you can plug it into a calculator and situate put if there is more
