Question 8 - End-of-Chapter Exercises - Chapter 2 Class 9 - Introduction to Linear Polynomials (Ganita Manjari

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Question 8 If the temperature of a liquid can be measured in Kelvin units as x K and in Fahrenheit units as y °F, the relation between the two systems of measurement of temperature is given by the linear equation y = 9/5 (x – 273) + 32. Find the temperature of the liquid in Fahrenheit if the temperature of the liquid is 313 K. If the temperature is 158 °F, then find the temperature in Kelvin. Let’s do (i) Temperature in Fahrenheit if temperature is 313 K Putting x = 313, and finding y y = 9/5 (x – 273) + 32 y = 𝟗/𝟓 (313 – 273) + 32 y = 9/5 × 40 + 32 y = 9 × 8 + 32 y = 72 + 32 y = 104 Thus, temperature is 104 °F Now, let’s do (ii) Temperature in Kelvin if temperature is 158 °F Putting y = 158, and finding x y = 9/5 (x – 273) + 32 158 = 𝟗/𝟓 (x – 273) + 32 158 – 32 = 9/5 (x – 273) 126 = 9/5 (x – 273) 126 × 5/9 = (x – 273) 14 × 5 = (x – 273) 70 = x – 273 70 + 273 = x 343 = x x = 343 Thus, temperature is 343 K