Substitute -4 for F and do the arithmetic.
.. C = (5/9)*(-4-32) = (5/9)(-36) = -20
-4 °F corresponds to -20 °C.
4 duh ....... 2+2=4........................
3 is the leading coefficient of the x term
It will be 50 hammers and 20 wenches
Hope this helps
F =

c + 32 Subtract 32 from both sides
F - 32 =

c Mutliply both sides by <span>

to cancel out the fraction
</span>

F - 17

= c Switch the sides to make it easier to read
c =
F - 17 <span>
</span>