Twenty more (+20) of a fifth of a number (.2x) is equal to 120. So, the equation would be .2x+20=120. To isolate x, subtract 20 from each side. So now we have .2x=100. To get rid of the .2 or 1/5, we have to multiply everything by the reciprocal of 1/5, or 5. So, 100(5)=.2x(5), or simplified, x=500. Hope this helps!
