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
Can you make any shortcut for this question
Answer:
If it is at -8, -8 then p is at 0,0
Step-by-step explanation:
Sorry, there is not much information given to answer.
Step-by-step explanation:
I am not sure bout this question sry
you reap what you sow ;)
Answer: The height of the building is 6.49 meters.
Step-by-step explanation:
This can be translated to:
"A building projects a 7.5 m shadow, while a tree with a height of 1.6 m projects a shadow of 1.85 m.
Which is the height of the building?"
We can conclude that the ratio between the projected shadow is and the actual height is constant for both objects, this means that if H is the height of the building, we need to have:
(height of the building)/(shadow of the building) = (height of the tree)/(shadow of the tree)
H/7.5m = 1.6m/1.85m
H = (1.6m/1.85m)*7.5m = 6.49m
The height of the building is 6.49 meters.
