7.)Write the third and fifth term of an arithmetic sequence whose fourth term is a and the common difference is 2.?

7)
Fourth term = a
Common difference = 2

Third term = (Fourth term) - (Common difference)
Hence, third term = a - 2

Fifth term = (Fourth term) + (Common difference)
Hence, fifth term = a + 2

#n = a + (n - 1) d
#4 = a + (4-1)2
#4 = a + 3(2)
#4 = a + 6

#3 = a + 2(2)
#3 = a + 4

#5 = a + 4(2)
#5 = a + 8

Fourth term is a
The sequence is a-3d, a-2d, a-d, a , a+d,.....
d=2
a-6 , a-4 ,a-2 , a , a+2, a+4,....
Fifth term is a+2

Given that 4rd term a = A+3d= A+3*2=A+6
So first term A= a-6
3rd term= A+2d= a-6+2*2= a-2
5th term= A+4d= a-6+4*2= a+2