Answer: y=6
Step-by-step explanation:
The given number is y.
According to the question,
Step 1 . subtracts three from the number (y-3), then doubles it
i.e. Final number = 2(y-3)
Step 2 . subtracts three again i.e. (2(y-3)-3), and doubles the number again
i.e. Final result = 2(2(y-3)-3)
If the result is his original number y, then
2(2(y-3)-3) =y
⇒ 2(2y-6-3)=y [ using distributive property]
⇒ 2(2y-9)=y
⇒ 2(2y)-2(9)=y [ using distributive property]
⇒ 4y -18=y
⇒ 4y -y= 18
⇒ 3y= 18
⇒ y= 6 [Divide both sides by 3]
Hence, y=6
