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
The linear rule should look like this y=a*x+b
As the function graph goes through the (0,0) point, the equation 0=a*0+b <=> b=0 must be true.
Now we only need to find a, using one of the points given. With (-4, 16):
16=-4*a <=> a=16/-4 <=> a= -4
So the rule looks the following way:
f(x)= -4*x
The answer to the question
Answer:
Step-by-step explanation:
<u>Number of those drive to school:</u>
<u>Number of those don't drive:</u>
<u>Probability:</u>
- P(Drive to school ' ) = 60/100 = 3/5
The distance between 1 - 10 1/4
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1 - 10 1/4 = -9 1/4
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Answer
-9 1/4
9 1/4 (in absolute value)
