Question

Explain why the expresion 2c+30 can be used to estimate the value of celsius tempertrue in degreees farhrenheit. Then use expression to estimate the value of -15 fahrenheit

Answer 1

Question

We know that there is a formula for conversion of Celsius to Fahrenheit:

$$F = 1.8 \cdot C + 32.$$

If we round off numbers in this formula, we will receive:

$$F = 1.8 \cdot C + 32 \approx 2 \cdot C + 30.$$

So, we can say that we can use formula $F = 2 \cdot C + 30$ to convert Celsius temperature into Fahrenheit degrees.

For conversion Fahrenheit into Celsius we can find next formula:

$$F = 2 \cdot C + 30 \Rightarrow 2 \cdot C = F - 30 \Rightarrow C = \frac{F - 30}{2} = \frac{F}{2} - 15.$$

According to this formula $-15{}^{\circ}F$ equal: $C = \frac{(-15)}{2} - 15 = -15 - 7.5 = -22.5{}^{\circ}C$.

Answer: $-22.5{}^{\circ}C$