Question

Suraj took a slice of pizza from the freezer and put it in the oven. The oven heated the pizza at a rate of 7.5^\circ7.5 ∘ 7, point, 5, degrees Celsius per minute, and it reached the desired temperature of 80^\circ80 ∘ 80, degrees Celsius after 121212 minutes.

Answer 1

y = 7.5t - 10

Explanation:

A linear equation is in the form y = mx + b, where y is a dependent variable, x is an independent variable, m is the rate of change and b is the value of y when x = 0.

Let y represent the temperature of the pizza and t represent the time the pizza spent in the freezer in minutes. Therefore:

y = mt + b

Since the oven heats the pizza at a rate of 7.5°C, therefore

y = 7.5t + b (we need to find b)

It takes 12 minute (t = 12) to reach a temperature of 80°C (y = 80), hence:

80 = 7.5(12) + b

80 = 90 + b

b = -10

This means that the initial temperature of the pizza when removed from the freezer is -10°C. The linear equation is:

y = 7.5t - 10