Hello :
the common ratio is r = -95-(-100)=5
the general terme is : un= u1+(n-1)r
un = -100 +(n-1)(5)
un =-100 +5n-5
un = 5n-105
The last term is : 100
un =100
5n-105 = 100
5n =205
n = 41 (Number of terms)
The last term is : u 41
<span>the sum is : S= (41/2)(-100+100)=0</span>
Answer:
Step-by-step explanation:
(6x+1)(9x-23)= 6x(9x-23)+1(9x-23)
= 54x²-138+9x-23
= 54x²+9x-161
Answer:
3.4
Step-by-step explanation:
Standard deviation of a population is defined as:
σ² = ∑(xᵢ − μ)² / n
The standard deviation of a sample is defined as:
s² = ∑(xᵢ − x)² / (n - 1)
It's not clear which one we have, so let's calculate both.
First, we must find the mean.
μ = (5+12+15+10+12+6+8+8) / 8
μ = 9.5
Now we find the squares of the differences:
(5-9.5)² + (12-9.5)² + (15-9.5)² + (10-9.5)² + (12-9.5)² + (6-9.5)² + (8-9.5)² + (8-9.5)²
= 80
Divide by n:
σ² = 80 / 8
σ² = 10
And take the square root:
σ = √10
σ ≈ 3.2
That's not one of the answers, so let's try the standard deviation of a sample instead of a population.
Instead of dividing by n, we'll divide by n-1:
s² = 80 / 7
And take the square root:
s = √(80/7)
s ≈ 3.4
So that must be it.
I think you can find it graphically by points through a table you create like:
let x = 0, and find the value of y
for example for the first equation when we let x = 0 you find y = 6 and be in the form of (0,6) then draw them or you can let x = -2 or -3 , etc as you like
to be more accurate you can find 3 pionts and start graphing them
these two equations are straight lines and they will intersect in a point
Answer:
37.8
Step-by-step explanation:
Set up a proportion using the values given in the diagram of similar triangles.
31.5/15 = x/18
Cross-multiply.
31.5(18) = 15x
Multiply.
567 = 15x
Divide both sides by 15.
37.8 = x
