<p>Please help, I don't understand this.
step 1) -[1/(1-a) - 1]
step2) -[1/(1-a) - (1-a)/(1-a)]
step 3) -a/(1-a)</p>
<p>I don't understand how step 2's units canceled to get step 3's. Basically the problem was simplified and I don't understand how, (even though it shows the steps)</p>
<p>Am I moron?</p>
<p>The denominator is the same, so you just distribute the negative and cancel the 1’s.</p>
<p>I don’t understand how to distribute the negative…</p>
<p>Like for making a division negative it would be -[(1-a)/(1-a)] = (-1+a)/(-1+a)?
When both the numerator are made negative, aren’t they STILL positive? So how could there be a change?</p>
<p>Because 1-a is a common denominator for both terms, you merely take 1 (the numerator of the first term) and subtract 1-a (numerator for the second term) and put that over the common deminator of 1-a.</p>
<p>1 minus 1-a is a. a over 1-a quantity times -1 is -a/(1-a).</p>
<p>Thanks I got it!</p>
<p>I don’t understand how they were able to add the -a and the (1-a) in the second term of step 2; how does that simplify without changing the value of the equation?</p>
<p>Thanks again</p>
<p>I don’t understand your question, but does this help…</p>
<p>step2) -[1/(1-a) - (1-a)/(1-a)]
step2.25) -[{1-(1-a)}/(1-a)]
step2.5) -[(1-1+a)/(1-a)]
step2.75) -[(a)/(1-a)]
step 3) -a/(1-a)</p>