4d/a - 9 = g for a
Add 9 to each side:
4d/a - 9 + 9 = g + 9
Cancel the 9's on the left side and we get:
4d/a = g + 9
Cross multiply:
4d = a(g + 9)
Divide each side of the equation by (g + 9) to isolate a:
4d/(g + 9) = a(g + 9)/(g + 9)
Cancel the (g + 9) on the right side, and we get:
a = 4d/(g + 9)
Add 9 to each side:
4d/a - 9 + 9 = g + 9
Cancel the 9's on the left side and we get:
4d/a = g + 9
Cross multiply:
4d = a(g + 9)
Divide each side of the equation by (g + 9) to isolate a:
4d/(g + 9) = a(g + 9)/(g + 9)
Cancel the (g + 9) on the right side, and we get:
a = 4d/(g + 9)