The sequence is an arithmetic sequence with
a₁ = -4
d = a₂ - a₁
d = -1 - (-4)
d = -1 + 4
d = 3
an = x
Sn = 437
General formula in arithmetic sequence
Formula to find nth term
an = a₁ + d(n - 1)
Formula to find sum of sequence (sn)
Sn = n/2 (a₁ + an)
We have to make an equation system based on the problem
plug the numbers into the formula
First equation
an = a₁ + d(n - 1)
x = -4 + 3(n - 1)
x = -4 + 3n - 3
x = 3n - 7
Second equation
Sn = n/2 (a₁ + an)
n/2 (a₁ + an) = 437
n/2 (-4 + x) = 437
n(x - 4) = 874
xn - 4n = 874
Solve the equation system by subtitution method
Subtitute x with 3n - 7 in the second equation
xn - 4n = 874
(3n - 7)n - 4n = 874
3n² - 7n - 4n = 874
3n² - 11n - 874 = 0
(3n + 46)(n - 19) = 0
n = -46/3 or n = 19
Because the number of terms shouldn't be negative, -46/3 isn't required, so the value of n is 19.
Solve for x, back to the first equatin
x = 3n - 7
x = 3(19) - 7
x = 57 - 7
x = 50
The solution is 50
Answer:
52 doses
Step-by-step explanation:
<h3>hope it help</h3>
<h2>#CRRYONLEARNING!</h2>
Your answer is A. Y=5- 1/3x
Answer:
The probability that Bentely will be selected first = 0.046
Step-by-step explanation:
The person will be randomly selected, it is not stated that sex is considered in the selection.
The total number of people present at the party = 10 + 12 = 22
The probability that Bentely will be selected first = 1/22
The probability that Bentely will be selected first = 0.046
Answer: x = -5, 3/2 y = 10, 7/2
Explanation:
y = 2x^2 + 6x - 10 (1)
y = - x + 5 (2)
=> 2x^2 + 6x - 10 = - x + 5
2x^2 - 7x - 15 = 0
(2x - 3)(x + 5) = 0
=> 2x - 3 = 0
2x = 3
x = 3/2
=> x + 5 = 0
x = -5
According to (2):
y = -x + 5
y = -(-5) + 5
y = 5 + 5 = 10
y = -x + 5
y = -(3/2) + 5
y = -(3/2) + 10/2
y = 7/2
