Question

integration Cos inverse 1 - x square by 1 + x squared DX

Answer 1

Here is your answer




Let the age of John be 5x and age of David be 7x

After 4 years, their ages will be 5x + 4 and 7x + 4

The sum of their ages = 56


According to the question,

5x + 4 + 7x + 4 = 56

12x + 8 = 56

12x = 56 - 8

12x = 48

x = \frac{48}{12}1248​

x = 4


∴ Age of John = 5x = 5 * 4 = 20 years

∴ Age of David = 7x = 7 * 4 = 28 years

Answer 2

This is your answer

5x + 4 + 7x + 4 = 56

12x + 8 = 56

12x = 56 - 8

12x = 48

x = \frac{48}{12}1248​

x = 4