This is a refreshing question!
We are given that
f(r)=ar+b, and
Sum f(r) =125 for r=1 to 5
Sum f(r) = 475 for r=1 to 10.
and we know, using Gauss's method, that
G(n)=sum (1,2,3.....n) = n(n+1)/2 or
G(n)=n(n+1)/2
Sum f(r) =125 for r=1 to 5
=>
sum=a(sum of 1 to 5) + 5b => G(5)a+5b=125 [G(5)=15]
15a+5b=125 ...................................................(1)
Similarly, Sum f(r) = 475 for r=1 to 10 => G(10)a+5b=475 [G(10)=55]
=>
55a+10b=475.................................................(2)
Solve system of equations (1) and (2)
(2)-2(1)
55-2(15)a=475-2(125) => 25a=225 =>
a=9
Substitute a=9 in 1 => 15(9)+5b=125 => 5b=-10
b=-2
Substitute a and b into f(r),
f(r)=9r-2
check: sum f(r), r=1,5 = (9-2)+(18-2)+(27-2)+(36-2)+(45-2)=135-10=125 [good]
We define the sum of f(r) for r=1 to n as
S(n)=sum f(r) for r=1 to n = 9(sum 1,2,3....n)-2n = 9n(n+1)/2-2n = 9G(n)-2n
S(n)=9n(n+1)/2-2n
checks:
S(5)=9(15)-2(5)=135-10=125 [good]
S(10)=9(55)-2(10)=495-20=475 [good]
Hence
(a)
S(n)=sum f(r) for r=1,n
= 9(sum i=1,n)+n(-2)
= 9(n(n+1)/2 -2n
=(9(n^2+n)/2) -2n
(b) sum f(r) for i=8,18
=sum f(r) for i=1,18 - sum f(r) for i=1,7
=S(18)-S(7)
=(9(18^2-18)/2-2(18))-(9(7^2-7)/2-2(7))
=1503-238
=1265
Answer:
∡S corresponds to ∡X
∡TXY = ∡RST
∡XTY = ∡SRT
∡XYT = ∡STR
Step-by-step explanation:
Answer:
6 units down
Step-by-step explanation:
Transformation is the movement of a point from its original position to a new position. If an object is transformed, all the point making the object is also transformed. There are four different transformations: Reflection, dilation, translation and rotation.
If y = f(x), y = f(x) + k is a translation k units up if k > 0 and is a translation k units down if k < 0
Given that the parent function is an absolute value represented by:
y = |x|
Therefore comparing y = |xl - 6 with y = f(x) + k, k < 0, therefore this is a translation of 6 units down
Answer:
2+m-1+m
Step-by-step explanation:
By combining like terms, the given expression and the above answer both simplify to ...
2m+1
___
The other available choices do not.
Answer:
Victor should buy Legend because it has a better unit rate
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Step-by-step explanation:
See attachment for complete question.
To determine which car has more gas efficiency, we have to calculate the slope of each car.
Vehicle 1: Legend
Take any two corresponding points from the table
The slope is then calculated using;
<em>This implies that this vehicle (legend) travels 18 miles per gallon of gas</em>
Vehicle 2: Supreme
Take any two corresponding points from the graph
The slope is then calculated using;
This implies that this vehicle (supreme) travels 16.7 miles per gallon of gas
<em>Base on the calculations above, Victor should buy Legend because it has a better unit rate</em>
