At noon, the temperature in promontory, california was
70°f. by midnight, the temperature had fallen to
40°f. what was the change in temperature over the 12-hour period?

Change in temperature is -30°F

Step-by-step explanation:

Given:

Temperature in noon : 70°F

Temperature by mid-night : 40°F

The change in temperature is measured by subtracting the second temperature from 1st. If the temperature increased then the change is positive and if the temperature decreased then the change is negative.

So,

Here

Change in temp = Temp at mid-night - temp in noon

= 40 - 70 = -30°F

Hence the change in temperature is -30°F ..

check above link.

graphically?   well, you graph them both, the solutions is where they both intersect each other, since there are two solutions, meaning they will meet twice, or namely the linear will run into the quadratic curve twice, and where they meet, those x,y coordinates are the solutions to the system.

really really sorry if i'm

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8         8

- 4= x