The value of the digit 5 in the ten millions place would be 50,000,000, where the digit 5 in the hundreds place would be 500. Therefore, that would be 5x as much. (I was having a hard time understanding, please reply and make it more clear, thanks and have a good day! =D)
To solve for y, apply the distributive property:

Then, subtract 12 from both sides and you will get:

Then solve for y, by dividing both sides by 10.
Your final answer will be y=1.2