The first term of an A.P is -8. The ratio of the 7th term to the 9th term is 5:8. Calculate the common difference of the progression

Answer 1

Where a=-8
(a+6d)/(a+8d)=5/8

(6d-8)/(8d-8)=5/8

It boils down too

8(3d-4)=5(4d-4)

2(3d-4)=5(d-1)

6d-8=5d-1

d=-1+8=7

Answer 2

Correction on the last part
R.H.S

5(d-1)=5d-5

Answer 3

8 - 5 is 3 ie 3 is the common difference

Answer 4

a = - 8
Ratio of the 7th and 9th term is a + 6d : a + 8d = 5:8
8(a+6d) = 5(a+8d)
8a+48d=5a+40d
48d - 40d = 5a + 8a
8d = -3a
d = -3a÷8
d = -3×(-8)÷8 = 3
Therefore common difference = 3

Answer 5

Science

Answer 6

Amazing lesson keep it up

Answer 7

Yes,great

Answer 8

This nice

Answer 9

thank you 😅
you're such a life saver

Answer 10

Thank u very much I appreciate. ❤

Answer 11

Thank you so much❤

Answer 12

5/8
A

Answer 13

5/8
a=-8
(a+6d)/(a+8d)=5/8
Sub -8 into a
(-8+6d)/(-8+8d)=5/8
Cross multiply
=-64+48d=-40+40d
Collect like terms
48d-40d=-40+64
8d=24
Divide both sides by 8
d=3

Answer 14

The first term of an AP is -8 the ratio of 7th term to the 9th term is 5:8 calculate the common difference

Answer 15

Find out more about

Answer 16

d=-1+8=7