Given the relation between The temperature in degrees Fahrenheit, F, is related to the temperature in degrees Celsius, C, by the equation:
[tex]F=\frac{9}{5}C+32[/tex]a) If C = 50 , F = ??
So, substitute with C at the given equation :
[tex]\begin{gathered} F=\frac{9}{5}\cdot50+32 \\ F=9\cdot10+32 \\ F=122 \end{gathered}[/tex]b) When F = -60 , We need to find C = ?
So, substitute with F and find C
[tex]\begin{gathered} -60=\frac{9}{5}C+32 \\ -60-32=\frac{9}{5}C \\ -92=\frac{9}{5}C \\ C=\frac{5}{9}\cdot-92=-\frac{460}{9}=-51\frac{1}{9}=-51.1 \end{gathered}[/tex]c) when need to solve the equation in case of : C = F
So, Substitute with F = C , then solve for C
[tex]\begin{gathered} C=\frac{9}{5}C+32 \\ C-\frac{9}{5}C=32 \end{gathered}[/tex]Multiply the all terms by 5 :
[tex]\begin{gathered} 5\cdot C-5\cdot\frac{9}{5}C=5\cdot32 \\ 5C-9C=160 \\ -4C=160 \\ \\ C=\frac{160}{-4}=-40 \end{gathered}[/tex]In the case of F = C , Both of them will be equal -40
[tex]F=C=-40[/tex]