Complete question:
Between the time iko woke up and lunchtime, the temperature rose by 11°. Then by the time he went to bed, the temperature dropped by 14°.
What is the net change in the temperature relative to when lko woke up?
Answer:
The net change in the temperature relative to when lko woke up =
°
Explanation:
Given that between his wake up time and lunch time, temperature rose by 11°. Let the new temperature be
and let the initial temperature(temperature before wakeup time) be
Since the temperature rose by 11°, the new temperature after Iko woke up, T1, would be derived by adding 11° to the initial temperature.
i.e, T1 = T + 11......................(1)
At bed time the temperature dropped by 14°. Therefore, the temperature would now be 14 less than the new temperature T1. It is expressed as:
T1 + (-14).......................... (2)
Let's substitute T + 11 for T1 in equation 2, we have:
T + 11 + (-14)
To find the expression for the net change in temperature, let's subtract the initial temperature T, from (T+11 -14) i.e,
ΔT = (T + 11 - 14) - T
Solving further, we have:
ΔT = T - T + 11 - 14
ΔT = 11 - 14
ΔT = -3°
Therefore, the net change in the temperature relative to when lko woke up is = -3°