Ubah skla 86f ke... C

C : R : F = 5 : 4 : 9

86 ° F - 32 °

= 54 °

= 5/9 × 54 °

= 30 ° C

c=5/9x(86-32)
  =5/9x54
  =30 derajat celcius
semoga bermanfaat :)