please someone answer this like im begging. you just need to find the matches, please ill give brainliest

15 point ! ~ see if you know the answer to both you!

Find the midpoint m of z1=(8+5i) and z2=(12+3i)

Sanya noticed that the temperature was falling at a steady rate of 1.4 degrees every hour from the time that she first checked her outdoor thermometer. by 6 a.m., the temperature had fallen 21 degrees. which expression can you use to find how many hours earlier she had first checked the thermometer?