Question

a chemist is heating water so it can dissolve a larger amount of sodium chloride. the waters temperature increases 7°c each minute from an initial temperature of 21°c. write an equation that shows how the temperature of the water in °c, y, depends on the number of minutes the chemist has been heating it, x. y =

Explanation:

Step1: Identify the slope - intercept form

The equation of a line is $y = mx + b$, where $m$ is the slope and $b$ is the y - intercept.

Step2: Determine the slope

The water's temperature increases $7^{\circ}C$ each minute. So the rate of change (slope) $m = 7$.

Step3: Determine the y - intercept

The initial temperature is $21^{\circ}C$. When $x = 0$ (at the start, 0 minutes of heating), $y=21$. So the y - intercept $b = 21$.

Step4: Write the equation

Substitute $m = 7$ and $b = 21$ into $y=mx + b$. We get $y=7x + 21$.

Answer:

$y = 7x+21$