In mathematical notation, ∑ means summation. So wherever you see the symbol, you have to sum over all elements in the set. Let's solve the question.
a. ∑m means, to sum all elements in the set m: ∑m = 12 + 15 + 20 + 30 = 77
b. ∑
means to sum all elements in the set f as the square of the elements f = 
c. ∑mf means to sum all elements as the product of the elements of m and f = (12×5) + (15×9) + (20
10) + (30×16) = 875
d. ∑
means to sum all elements as the product of the square of m and f = 
Answer:
slope=1
Step-by-step explanation:
Formula for slope is m =
y2 - y1
/x2 - x1
you will then use 7-8/4-5
Then -1/-1 which will simplify to 1
Answer:the third one
Step-by-step explanation: so if you are doing that, it is simple. If it is the power of something, then you go left to multiply, and go right to divide. Then, you will get your answer, but when you are done with that, add then subtract . There, you will find your new answer.
In this case, the pattern is the number, in this case, 3, multiplied by the number below it.
See?
Hope this helped :)
