Write the sum using summation notation, assuming the suggested pattern continues. 64 + 81 + 100 + 121 + + n2 +

Step-by-step explanation:

The given series is

It can be seen that all the numbers are perfect square.

hence, the given series is of squares and it can be written as

If we assuming the pattern continues till infinity , then by using summation the above series will be written as

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional

i think its a and d

step-by-step explanation: