It is asking you to find the sum of k^2 - 1 from k=1 to k=4. Since that is only 4 numbers, calculating the sum by hand wouldn’t be that bad.
(1^2 - 1) + (2^2 - 1) + (3^2 - 1) + (4^2 - 1) = 26
The easier way to find the sum is to use a few simple formulas.
When we have a term that is just a constant c, the formula is c*n.
When we have a variable k, the formula is k*n*(n+1)/2.
When we have a squared variable, the formula is k*n*(n+1)*(2n+1)/6.
In this case, we have a squared variable k^2 and a constant of -1.
So plug in n=4 to the formulas:
4*5*9/6 - 1*4 = 26
The answer is 26
Answer:
x = -8
Step-by-step explanation:
y = 3x/4
Substitute the value of -6 into y.
-6 = 3x/4
Multiply both sides by 4.
-24 = 3x
Divide both sides by 3.
x = -8.
Answer:
179.59
Step-by-step explanation:
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X=33 and Y= 57
Step by step explanation if you see the right angle at 57 degrees it part of x so x plus 57 is 90 and 90 minus 57 is 33 so x is 33 and x and y also form a right angle so x plus y should equal 90 and 90 minus 33 is 7 so that’s Y
$10.83 because you need to divide 6.50 by .6 to get that answer approximately.
