Question

after 12 years I shall be 3 times as old as I was 4 years ago find my present age​

Answer 1

Letting x = present age

x + 12 will be my age 12 years from now.
3(x-4) will be three times as old as I was 4 years ago

x+12 = 3(x-4)
Solve for x

x+12 = 3x - 12
subtract x from both sides
12 = 2x - 12
add 12 to both sides
24 = 2x
divide both sides by 2
12 = x

My present age is 12 years

Check: x+12 = 3(x-4)
12+12 = 3(12-4)
24 = 3(8)
24 = 24

Answer 2

Given:

After 12yrs, I shall be 3 times as old as I was 4 years ago.

To Find :

My Present age= ?

Solution:

Let my present age be x years.

After 12 years, my age will be (x + 12) years.

4 years ago , my age was (x -4) years.

It is given that after 12 years I shall be 3 times as old as I was 4 years ago.

$\sf \therefore \: x + 12 = 3(x - 4) \\ \sf \: x + 12 = 3x - 12 \\ \sf x - 3x = - 12 - 12 \\ \sf - 2x = - 24 \\ \sf x = \frac{-24}{-2} \\ \\ \sf x = 12 \\ \\ \sf \red{ \underline{ \: my \: present \: age \: is \: 12 \: years}}$