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 = 18
Step-by-step explanation:
b squared + x squared = 30 squared
Answer:
≥ and ≤ will both be solid dots, as it includes the number
x ≥ -7 is everything greater than -7; x ≤ 4 is everything less than 4.
to include both, you'd click -7, drag right, and stop at 4
X will be 35 but idk the formula
here. I don't know if its right but i hope it is.
