98.4 is equal to 100%. So now we know that x is 120% of the output value, so we can write it down as x=120%. Now we have 2 simple equations. Now we want to write it like this 98.4/x=100%/120%. Now we solve:
98.4/x=100/120
(98.4/x)*x=(100/120)*x Multiply both sides by x.
98.4=0.833333333333*x Divide both sides of the equation by (0.833333333333) to get x
