The temperature was very cold. Then the temperature doubled. Then the temperature dropped by 10 degrees. Then the temperature increased by 40 degrees. The temperature is now 16 degrees. What was the starting temperature?

Answer: the starting temperature is - 7 degrees.

Step-by-step explanation:

Let x represent the starting temperature.

Then the temperature doubled. It means that it became 2x degrees

Then the temperature dropped by 10 degrees. It means that it became 2x - 10 degrees.

Then the temperature increased by 40 degrees. It means that it became 2x - 10 + 40 = 2x + 30 degrees.

If the temperature is now 16 degrees, it means that

2x + 30 = 16

2x = 16 - 30

2x = - 14

x = - 14/2

x = - 7 degrees

x: starting temperature

dropped 10

increase : 40

total 16

x-10+40=16

x=-14