Is there a shortcut formula to use whenever one of the values inside a formula changes?

Question

I have this formula.

true=base×(1+A)×(1+B−C)×(1−D)×(1+E−F)×(1−G)

If the E increases its value, is there a way to know the adjusted true without having to calculate the whole formula again using the adjusted E?

For example this.
108.9=200×(1+0.1)×(1+0.4−0.2)×(1−0.5)×(1+0.5−0.4)×(1−.25)

If E increased by 0.5 making it 1, how do I get the adjusted true which is 158.4 without recalculating everything again?

Any of the letters can change it's value.

Answer 1

keep only the required variable part on the right hand side and send all the other variables to the left hand side . Solve left hand side. Now you will have a constant value on left hand side.  Now if right hand size value increases, we can edit it and solve for the desired variable.