Question

Find value of a if distance between A(-3, -14) and B (9a, -5) is 9 unit.

Answer 1

dear student

$$\begin{gathered} (9a+3{)}^2+(-5+14{)}^2=9^2 \\ (9a+3{)}^2+(9{)}^2=9^2 \\ 9a+3=0 \\ a=-3 \end{gathered}$$