-2x + 4 < -3 , where x is the number of hours after noon
or
2x > 7
x > 3.5
notice the switch in the inequality sign because we divided by a negative
or
2x > 7
x > 3.5
notice the switch in the inequality sign because we divided by a negative
We know that the temperature in Toronto at noon is 4°C and it drops 2°C every hour. Let's assume that after x hours, the temperature drops below -3°C.
The initial temperature at noon is 4°C, and since it is dropping 2°C every hour, we can calculate the temperature after x hours as: 4 - 2x.
We want to find the number of hours after which the temperature will be below -3°C. Therefore, we can set up the following inequality:
4 - 2x < -3
Simplifying this inequality, we get:
-2x < -3 - 4
-2x < -7
To solve for x, we need to divide both sides of the inequality by -2, but we must reverse the inequality sign because we are dividing by a negative number:
x > (-7) / -2
x > 7/2
x > 3.5
Therefore, the inequality that can be used to find the number of hours, x, after which the temperature will measure below -3°C is x > 3.5.