The inner LCD is x. Multiply each term by x to clear out the inner fraction
So up top we have 1*x = 1x = x and we also have (1/x)*x = x/x = 1 meaning that 1 - (1/x) turns into x - 1 after multiplying the top terms of the complex fraction by x
Do the same for the denominator of the complex fraction. Multiply that term by x to get 2x