Question

a number decreased by 6 is 15 find its number​

Answer 1

Answer:

Let the number be x

$x - 6 = 15 \\ x = 15 + 6 \\ x = 21$

Therefore the number is 21

Answer 2

Answer:

Let the number be x

According to the question x - 6 = 15

=> x = 15 + 6 = 21

x = 21

Required number is 21