Respuesta :

Best to ask, "How do I solve this equation for n?"

1.  Div. both sides by -4, along the way to isolating 8n-3 and then n:
     8n-3 = -21
2.  Add 3 to both sides:   8n = -18
3.  Solve for n:                   n = -18/8 = -9/4 (answer)