Question

Three times a number increased by 12 is equal to five times the same number decreased by 18. Find the number.

the answer is 15. but i need the solution

Answer 1

Explanation:

Let us say that the number is x

Now , According to the question ,

let us start by considering the L.H.S first i.e. three times a number increased by 12 i.e. 3^x+12 -------(1)

Now , consider R.H.S i.e. Five times the same number decreased by 18 i.e.

5^x-18-------------(2)

Now we are given that both the numbers are equal so here we equate eqn (1) and eqn (2)

⇒ 3x + 12 = 5x - 18

⇒ 12 +18 = 5x - 3x

⇒ 30 = 2x

⇒ 2x = 30

⇒ x = 30/2

⇒ x = 15

∴ Hence 15 is the required number