Question

From midnight to 1:00am in January the temperature dropped 19 F. After drooped,the outside temp was -20 f. What was the temperature a midnight?

Answer 1

I am pretty sure it is -1 f...

Answer 2

Let's call the midnight temperature ' T ' . (Clever ?)

After the temperature drooped 19 degrees, it must have been (T - 19).

But we know that it was -20 after it drooped 19 degrees, so we can say

T - 19 = -20

Add 19 to each side of the equation, and then it says:

T = -1 .

See that ? The answer just about jumped out at you !