Answer:
$3800
Step-by-step explanation:
When simple interest is added to the principal amount, the sum increases linearly with time. Essentially, you are asked for the y-intercept of a line that goes through the points (2, 6200) and (3, 7400). You can use the 2-point form of the equation of a line to find it:
y = (y2 -y1)/(x2 -x1)(x -x1) +y1
y = (7400 -6200)/(3 -2)(x -2) +6200 . . . . fill in given points
y = 1200(x -2) +6200 . . . . . . . . . simplify some
y = 1200x -2400 +6200 . . . . . . simplify more
y = 1200x +3800 . . . . . . . . . . . . . completely simplify
When the number of years (x) is zero, the amount is 3800. The principal is $3800.
_____
The account is earning $1200 per year on a principal of $3800. The interest rate is about 31.6%, an unusually high value.
_____
<em>Alternate solution</em>
You can recognize that the interest earned in one year is 7400 -6200 = 1200. Since this is simple interest, the amount of interest earned each year is the same, so in 3 years, the account has earned 3×$1200 = $3600 in interest. Then the original principal amount must be ...
$7400 -3600 = $3800 . . . . . principal amount
Answer:
(-1, 5)
Step-by-step explanation:
Rearrange the the first equation to have y on one side and all other values on the other side
y = 1 - 4x
since both of the equations are equal to y, set them equal to each other an solve for x.
1 - 4 x = x + 6
-5 = 5 x
x = -1
plug this back into the second equation to get y = 5
Answer:
66 cm
Step-by-step explanation:
Let's define the circumference first.
It is the boundary of any curved geometric figure specially circle.
We are given the diameter of the circle in the diagram
The diameter is:
d = 21 cm
to find the circumference, we have to find the radius of the circle first.
As radius is half of diameter
d = r/2
= 21/2
= 10.5 cm
The formula for circumference is:

The circumference is 66 cm ..
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