3n + 9(2n – 5) = -3 n =

n = 2 im guessing

Step-by-step explanation:

3n + 9 (2n - 5) = -3n

3n + 18n - 45 = -3

21n - 45= - 3

21n = -3 + 45

21n = 42

n = 2

hope that helps and there are multiple ways to do it the way i did it was solve for n and i got 2:))

step-by-step explanation:

you can add the two numbers and divide the result by 2. or you can find the gap between the two numbers and add half of this to the smaller number.