Answer:
Step-by-step explanation:
we have
Remember that
in this problem we have
Convert 
to minutes
so
Convert 
to seconds
therefore
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: 59$
Step-by-Step Explanation:
Let the discounted rate be ‘x’
No. of visits = 4
Total Amount for the visits = 4 * x = 4x
Additional cost = 25$
Total Amount = 261$
Therefore,
= 4x + 25 = 261
= 4x = 261 - 25 = 236
=> x = 236/4 = 59
Therefore, x = 59
Hence, discounted rate = 59$
Answer:
8x- 38
Step-by-step explanation:
3(x-6)+5(x-4)
Distribute
3x- 18+5x -20
Combine like terms
3x+5x -18-20
8x- 38
(-3x + 15) + (-3x + 2)
Simplify by combining like terms.
-6x + 17
-6x + 17
