The temperature at 12 noon was 10°C above zero. If it decreases at the rate of 2°C per hour until midnight, at what time would the temperature be 8°C below zero? What would be the temperature at mid-night?

The answer to your question is a) 21:00   b) -14°C

Step-by-step explanation:

Data

Temperature at noon = 10°C

rate = 2°C/hour

a) Do a chart to solve this problem

            Time          Temperature

            12:00                10°C

             13:00                 8°C

             14:00                 6°C

             15:00                 4°C

             16:00                 2°C

             17:00                  0°C

              18:00                -2°C

             19:00                -4°C

             20:00               -6°C

             21:00                -8°C

b)

            22:00                -10°C

             23:00               -12°C

            24:00                -14°C

x= -3 and

step-by-step explanation:

to find the roots of a cubic, use division or factoring to find the factors then set equal to 0. as this is a difference of cubes, it factors into

where a is the cube root of .

here   this is 27 and the cube root of 27 is 3. so we write using the form:

.

set each factor to 0 and solve for x.

x-3=0

x=3

the quadratic expression does not factor and must be solved using the quadratic formula.

where a = 1, b=3, and c=9

this cubic has two complex roots.