The number is 9 set it up you will have n over 3 plus five equals 8 . substract 5 from both sides then you will have n over 3 equals 3 . you have to multiply the n over 3 by 3 to get rid of the 3 and you multiply the 3 on the other side by three to get n equals 9
We must fine the conversion for this, so we have to divide $270 by 200€ to get 1.35 Dollars for every Euro.. Now we multiply 300 by 1.35 to get 405 dollars
Basically, going from fahrenheit to celcius, you have to Deduct 32, then multiply by 5/9. So just reverse it, instead, you multiple it by the reciprocal, which is "9/5" then you add 32. Simple. :)