(I’m not sure if the A is part of the question or if A is what question you’re answering but I’ll work o for both)
A(q - 8) = 23
Multiply everything inside the brackets by A:
aq- 8a = 23
Divide both sides by a to isolate q - 8a:
q - 8a = 23 / a
Add 8a to both sides to isolate q:
q = 23 + 8a² / a
Without the A:
q - 8 = 23
Add 8 to both sides to isolate q:
q = 31
Sorry if I misunderstood but I hope I helped you, have a great day!!