Answer:
(a;b)={(17; 64); (64; 17)}
Step-by-step explanation:
a+b=81 => b=81-a
a*b=1088
a*(81-a)=1088
-a²+81a=1088
a²-81a+1088=0
a²-64a-17a+1088=0
a(a-64)-17(a-64)=0
(a-17)(a-64)=0
=> a=17 and a=64
for a=17 => b=81-17=64
for a=64 => b=81-64=17
(a;b)={(17; 64); (64; 17)}
Answer:
Only 4 is the right answer. The rest all are false.
Answer: $15385 should be deposited.
Step-by-step explanation:
The principal was compounded monthly. This means that it was compounded 12 times in a year. So
n = 12
The rate at which the principal was compounded is 7.8%. So
r = 7.8/100 = 0.078
It was compounded for 4 years. Therefore,
t = 4
The formula for compound interest is
A = P(1+r/n)^nt
A = total amount in the account at the end of t years. The total amount is given as $21000. Therefore
21000 = P (1+0.078/12)^12×4
21000 = P (1+0.078/12)^48
21000 = P (1+0.0065)^48
21000 = P (1.0065)^48
P = 21000/1.365
P = $15385
<h3>
Answer: 270.58 dollars</h3>
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Work Shown:
- A = account value after t years
- P = principal or amount deposited = 800
- r = interest rate in decimal form = 0.06
- n = number of times we compound per year = 1
- t = number of years = 5
So,
A = P*(1+r/n)^(n*t)
A = 800*(1+0.06/1)^(1*5)
A = 1070.58046208
A = 1070.58
After five years, the account will have $1,070.58 in it.
The amount of interest earned is A-P = 1070.58 - 800 = 270.58 dollars.
100 divided by 2 is 50 and then divided by 6 is 8.333333 but you just round that to 8$.
