The common difference, d, in an arithmetic sequence whose fourth

term is 16 and whose seventh term is 31.

Answer: 5

Step-by-step explanation:

Arimethic progression

An=a1 + (n-1) d

An = nth term

A1 = first term

N = nth position

D = common difference

For the 4th term=16

A4=a1 + (n-1) d

16=a1 + (4-1) d

16=a1+3d ... equation 1

For the 7th term=31

A7=a1 + (n-1) d

31=a1 + (7-1) d

31=a1+6d ... equation 2

Subtract equation 1 from 2

31=a1+6d

16=a1+3d

15=3d

D=15/3

D=5

Common difference is 5