The 7th and the 20th term are 34 and 112 respectively. Find the Arithmetic Progression (A.P)

2 answers

112 = a + 19 d
34 = a + 6 d
-------------------------subtract
78 = 13 d
d = 6

a + 6*6 = 34
a = -2
HOW DID YOU GET 112=a+19d and 34=a+6d