Hey there!
If r = - 1/2 the substitute it into the question!
23 + 3/5(-1/2) = ?
3/5(-1/2) = -3/10 = ?
23 + (-3/10) = ?
Solve above and you have your answer!
Therefore, your answer is most likely: 227/10 ☑️
Good luck on your assignment and enjoy your day!
~LoveYourselfFirst:)