Answer:
4x+x=40
5x+40
x=8
8, 32
Step-by-step explanation:
Let the amount deposited (principal) be x, then the amount after the required time = 2x.
A = P(1 + r/n)^nt: where A is the future value = 2x, P is the principal = x, r is the rate = 0.75%, n is the number of accumulation in a year = 12, t is the number of years.
2x = x(1 + 0.0075/12)^12t
2 = (1 + 0.000625)^12t
log 2 = 12t log (1.000625)
log 2 / log (1.000625) = 12t
1109.38 = 12t
t = 92 years
Find the total cost of producing 5 widgets. Widget Wonders produces widgets. They have found that the cost, c(x), of making x widgets is a quadratic function in terms of x. The company also discovered that it costs $15.50 to produce 3 widgets, $23.50 to produce 7 widgets, and $56 to produce 12 widgets.
OK...so we have
a(7)^2 + b(7) + c = 23.50 → 49a + 7b + c = 23.50 (1)
a(3)^2 + b(3) + c = 15.50 → 9a + 3b + c = 15.50 subtracting the second equation from the first, we have
40a + 4b = 8 → 10a + b = 2 (2)
Also
a(12)^2 + b(12) + c = 56 → 144a + 12b + c = 56 and subtracting (1) from this gives us
95a + 5b = 32.50
And using(2) we have
95a + 5b = 32.50 (3)
10a + b = 2.00 multiplying the second equation by -5 and adding this to (3) ,we have
45a = 22.50 divide both sides by 45 and a = 1/2 and using (2) to find b, we have
10(1/2) + b = 2
5 + b = 2 b = -3
And we can use 9a + 3b + c = 15.50 to find "c"
9(1/2) + 3(-3) + c = 15.50
9/2 - 9 + c = 15.50
-4.5 + c = 15.50
c = 20
So our function is
c(x) = (1/2)x^2 - (3)x + 20
And the cost to produce 5 widgets is = $17.50
2 to the 30 power is <span>1073741824</span>
