The 4th term of an AP is equal to 3 times its 1st term and 7th term exceeds twice the third term by 1. Find the first term and common difference
Attachments:
Answers
Answered by
2
Given a4 = 3a1
(a + 3d) =3a Hence, 2a = 3d Therefore, a = 3d/2 and also given that a7 = 2a3 + 1 (a + 6d) = 2(a + 2d) + 1 a + 6d = 2a + 4d + 1 a = 2d – 1 (3d/2) = 2d – 1 d/2 = 1
Therefore, d = 2 a = 3d/2 = 3
(a + 3d) =3a Hence, 2a = 3d Therefore, a = 3d/2 and also given that a7 = 2a3 + 1 (a + 6d) = 2(a + 2d) + 1 a + 6d = 2a + 4d + 1 a = 2d – 1 (3d/2) = 2d – 1 d/2 = 1
Therefore, d = 2 a = 3d/2 = 3
Similar questions