Liquid helium boils at 4.2 K what is this temperature on the F scale

I keep getting it wrong here is what I did: (the formula i worked out)

Fahrenheit = (((573.15-K)*9)/5)+32
= (((573.15-4.2)*9)/5)+32
=-516.2

RIGHT ANSWER :-452F but i'm not sure how they got there...

Use this formula instead, its easier.

Kelvin To Fahrenheit:
((Kelvin - 273) * 1.8 ) + 32; note: 1.8 = 9/5

So,

( ( 4.2 - 273 ) *1.8 ) +32 = -451.84 F

Note: Make sure you are doing your order of operations correctly. Do it like: 4.2 - 273, take that number times 1.8, then add 32 to the number on your calculator.

-452.11 F
-268.95 C
7.56 R
4.20 K