Asked by Liji
In an A.P ratio of 3rd term and 5th term is 3:7.
a)Find the ratio of the 4th and 6th term?
b)Find the ratio of the 6th and 12th term?
a)Find the ratio of the 4th and 6th term?
b)Find the ratio of the 6th and 12th term?
Answers
Answered by
Damon
1 a
2 a+d
3 a+2d
4 a+3d
5 a+4d
n a + (n-1)d
(a+2d)/(a+4d) = 3/7
3 a + 12d = 7a + 14 d
4a=-2d
d = -2a
fourth/sixth (a+3d)/(a+5d)
= (a-6a)/(a-10a)
= -5a/-9a
= 5/9
etc
2 a+d
3 a+2d
4 a+3d
5 a+4d
n a + (n-1)d
(a+2d)/(a+4d) = 3/7
3 a + 12d = 7a + 14 d
4a=-2d
d = -2a
fourth/sixth (a+3d)/(a+5d)
= (a-6a)/(a-10a)
= -5a/-9a
= 5/9
etc