Question

On a very cold morning, it was -7°F. As the day went on, the temperature rose 3 degrees each hour. Which equation shows the temperature over time?
A.y=-3x-7
B.y=-3x+7
C.y=3x-7
D.y=3x+7

Answer 1

Answer:

The equation shows the temperature over time will be:

• $y = 3x - 7$

Hence, option (C) is correct.

Step-by-step explanation:

We know that the slope-intercept form of the line equation is

$y=mx+b$

where m is the rate of change or slope and b is the y-intercept

• Let 'y' be the temperature

• Let 'x' be the time in the hour

Given that one very cold morning, it was -7°F.

Thus, the y-intercept = b = -7

Given that as the day went on, the temperature rose 3 degrees each hour.

Thus, the rate of change = slope = m = 3

Thus, substituting m = 3 and b = -7 in the equation

$y = mx+b$

$y = 3x + (-7)$

$y = 3x - 7$

Therefore, the equation shows the temperature over time will be:

• $y = 3x - 7$

Hence, option (C) is correct.