What is the common difference of the arithmetic sequence-20,-16,-12,-18

common difference = 4

Step-by-step explanation:

common difference is the difference between the successive term and its preceding term.

let's take the successive term of -20 that is - 16

common difference (d) = successive term - preceeding term

= -16 -(-20)

= -16 + 20

= 4

if we take the successive term of -16 that is -12

we'll get the same common difference.

d = -12 -(-16)

d = -12 + 16

d = 4

this means that the common difference for an AP remains constant.

i dont know sorry

step-by-step explanation:

n=9

step-by-step explanation:

7 times a number = 7n

decreased by 13 = 7n-13

same as is =

5 times the number = 5n

increased by 5 = 5n+5

7n-13 = 5n+5

2n=18

n=9