i have the following formules:
a = ?
b = (a + 650 * 2a/5.5) + (a * 450)
c = (b / 4) - 270
when i enter a = 30, c will be 10238.
now i need a formula where i can enter d = 10238, and it calculates f = 30.
I'm really confused, i hope somebody can help me.