the fifth term of an arithmetic progression is 19,and the fourteenth term is 55. Find its first term

2 answers

"the fifth term of an arithmetic progression is 19"
----> a+4d = 19
" the fourteenth term is 55"
----> a+13d=55

subtract the two equations:
9d = 36
d = 4

in a+13d = 55
a + 13(4) = 55
a = 3
Correct