Let's set x for the temperature of dry ice.
Let's set y to for outside temperature.
Now, we have the next statement "The temperature of dry ice is -109.3 degrees Fahrenheit less than the outside". Then, we can write the next equation:
x = -109.3 - y
To find the outside termperature, we need to solve the equation for y.
Then, the outside temperature is given by the next equation;
y=-109.3 - x
