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
Given :
Service cost , c = $40.
Amount paid for each message , m = $0.02 .
To Find :
Equation represents the total cost C in dollars for a month when eric send t text message.
Solution :
Let , total cost be C .
It is an linear equation with slope equal to 0.02 and y-intercept equal to 40.
So ,
Hence, this is the required solution.
Answer:
A=14cm²
Step-by-step explanation:
A=hbb
2=7·4
2=14cm²
Answer:
Part D is correct
Step-by-step explanation:
Answer:
1. Positive, 1+2=3
2. Negative, -1-2=-3
Step-by-step explanation:
If you look at both in a graphing perspective, the point (1,2) is in Quadrant I. likewise, adding 2 to the x-coordinate will also result in the point (3,2), also in Quadrant I, where the x coordinate is positive. The point (-1,2) is in Quadrant II, and adding -2 to the x coordinate keeps it in Quadrant II, where the x-coordinate is negative.
