Question

a indicação de uma temperatura na escala fahrenheit excede em duas unidades o dobro do correspondente na escala Celsius essa temperatura é

a) 300 °c
b) 170°c
c)150°c
d)100°c
e)50°c

Answer 1

F = 2C + 2

Escala Termometrica:

C/5 = F - 32/9
C/5 = 2C + 2 - 32/9
C/5 = 2C + 30/9
5(2C - 30) = 9C
10C - 150 = 9C
-150 = 9C - 10C
-150 = - C
C = 150°C

Answer 2

$\tt 9tc\:=\:5\cdot \left(2tc\:-\:30\right)\\\\\\\tt 9tc=10ct-150\\\\\\\tt 9tc-10ct=10ct-150-10ct\\\\\\\tt -ct=-150\\\\\\\displaystyle \frac{-ct}{-t}=\frac{-150}{-t}\\\\\\\boxed{\tt C=150^\circ}$