In the following A.P., find the missing terms:
□, 38, □,□,□, – 22
Given: a2 = 38 and a6 = –22
We know that,
an = a + (n – 1)d
a2 = a + (2 – 1)d
38 = a + d …(i)
and a6 = a +(6 – 1)d
–22 = a + 5d …(ii)
Solving linear equations (i) and (ii), we get
a + d – a – 5d = 38 – (–22)
⇒ –4d = 60
⇒ d = –15
Putting the value of d in eq. (i), we get
a + (–15) = 38
⇒ a – 15 = 38
⇒ a = 53
Now, a3 = a + 2d = 53 + 2(–15) = 53 – 30 = 23
a4 = a + 3d = 53 + 3(–15) = 53 – 45 = 8
a5 = a + 4d = 53 + 4(–15) = 53 – 60 = –7
Hence, the missing terms are 53, 23, 8 and –7