exam oriented an important question from ML aggarwal, class 10th, chapter 7, ratio and proportion, Avichal publication
It is given that If a + c = mb and 1/b + 1/d = m/c,
Then we have to prove that a, b, c and d are in proportion.
Question 15, exercise 7.2
Solution:
It is given that
a + c = mb and 1/b + 1/d = m/c
a + c = mb
Dividing the equation by b
a/b + c/d = m ……. (1)
1/b + 1/d = m/c
Multiplying the equation by c
c/b + c/d = m …… (2)
Using equation (1) and (2)
a/b + c/b = c/b + c/d
So we get
a/b = c/d
Therefore, it is proved that a, b, c and d are in proportion.