Answer:
zero point zero two
Step-by-step explanation:
Function rule: a = 20w + 115
Slope: 20
Initial value: 115
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We start with $115 in the account. This is the initial value. Each week we add on $20.
So we add $20 for 1 week
We add 2*20 = $40 for 2 weeks
We add 3*20 = $60 for 3 weeks
etc etc
In general, we add 20*w dollars for w weeks onto 115 to get a = 20w+115
The slope is 20 because this is the rate of change, ie how fast the account grows. It grows 20 dollars per week.
Answer:
2,535
Step-by-step explanation:
Given:
Total amount invested = $9,000
interest rates = 4% and 6%
Let x be the part of 9,000.
Note that annual return on each investment is the same.
0.04x = 0.06(9,000 - x)
0.04x = 540 - 0.06x
0.04x + 0.06x = 540
0.10x = 540
x = 540/0.10
x = 5,400
0.04x = 0.06(9,000 - x)
0.04(5,400) = 0.06(9,000 - 5,400)
216 = 0.06(3,600)
216 = 216
total interest for the year : 216 + 216 = 432
Interest = pricipal * interest rate * term
432 = 9,000 * interest rate * 1 yr
432/9,000 = interest rate
0.048 = interest rate
Interest rate would be 4.8% to get the same interest from the whole 9,000.