The temperature at sunrise was -2 degrees fahrenheit. the temperature at sunset was 18 degrees warmer than it was at sunrise. what was the temperature at sunset?

a) -20 degrees fahrenheit
b) -16 degrees fahrenheit
c) 20 degrees fahrenheit
d) 16 degrees fahrenheit

d) 16 degrees Fahrenheit

Step-by-step explanation:

What do we know? Initial temperature: -2. Then the temperature rose by 18 degrees. We can express this mathematically:

If you are not particularly comfortable with negatives, you can rewrite this expression as such:

Thus the temperature at sunset was 16 degrees Fahrenheit.

step-by-step explanation:

what grade level is this? need to know so i can look in my old textbooks!

let's cover over the formula of the vertex:

y = a(x – h)^2 + k

in this formula, (h,k) are the vertex, always remember that the positive or negative value of the vertex is based on the sign it has.

for example, if the vertex is -3,-6 then both the x and y value would have the positive sign attached to it and if it were a positive x and y value, then a negative sign would be attached to it.

with that being said, for our problem the x value is a positive one so we are looking for a number with a negative sign next to it, in this case the first and second choice.

however, for the first answer choice it isn't quite part of the formula so we know that the answer choice correctly displays the x value.

to confirm, we can see if the -1 fits correctly with the second answer choice, and as mentioned above a negative number will have a positive sign attached to it. so, for our problem we can see that -1 has been changed to +1, so we can confirm that the second answer choice is correct.

hence, our final answer is y=(x - 1)^2 + 1