Adv
deepaksoni
  • 0
Guru

If k + 3, k + 2, 3k – 7 and 2k – 3 are in proportion, find k.

  • 0

This is an important ques from the Book ML Aggarwal class 10th,, chapter – 7, ratio and proportion.

Here four numbers with a constant K are given in proportion and we have to find the value of K

Question 8, exercise 7.2

Share

1 Answer

  1. Solution:

    It is given that

    k + 3, k + 2, 3k – 7 and 2k – 3 are in proportion

    We can write it as

    (k + 3) (2k – 3) = (k + 2) (3k – 7)

    By further calculation

    2k2 – 3k + 6k – 9 = 3k2 – 7k + 6k – 14

    3k2 – 7k + 6k – 14 – 2k2 + 3k – 6k + 9 = 0

    k2 – 4k – 5 = 0

    k2 – 5k + k – 5 = 0

    k(k – 5) + 1(k – 5) = 0

    (k + 1) (k – 5) = 0

    So,

    k + 1 = 0 or k – 5 = 0

    k = -1 or k = 5

    Therefore, the value of k is -1, 5.

    • 0
Leave an answer

Leave an answer

Browse

Choose from here the video type.

Put Video ID here: https://www.youtube.com/watch?v=sdUUx5FdySs Ex: "sdUUx5FdySs".

Captcha Click on image to update the captcha.

Related Questions