document.write( "Question 76649: I need to solve for x. I believe the answer if 4 but I have no idea how to start.
\n" ); document.write( "(2x-3/x-1)-(x-1/x+2)=(2x-5/x+2)+(2-x/1-x)
\n" ); document.write( "

Algebra.Com's Answer #54971 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Sort of a long problem. Given:
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "Notice that the denominators are (x - 1), (x + 2), and (1 - x). Sure would be nice if
\n" ); document.write( "that denominator (1 - x) was (x - 1) so it was like the other one. So let's apply a little
\n" ); document.write( "math trick to the last term on the right side. Let's multiply the numerator and the denominator
\n" ); document.write( "inside the parentheses by \"%28-1%29%2F%28-1%29\". Since the numerator and the denominator of that multiplier
\n" ); document.write( "are equal, it is the same as multiplying the fraction inside the parentheses by 1, so it does
\n" ); document.write( "not change anything ... except it reverses the signs of the terms in the parentheses.
\n" ); document.write( "When you do that manipulation, the last term on the right side becomes:
\n" ); document.write( ".
\n" ); document.write( "\"%28%28x-2%29%2F%28x-1%29%29\"
\n" ); document.write( ".
\n" ); document.write( "and the equation becomes:
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "Now we're ready to rumble! Let's multiply every term on both sides by the product of
\n" ); document.write( "the common terms in the denominator. In other words, let's multiply everything by the
\n" ); document.write( "product (x-1)*(x+2). When we do, the problem becomes:
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "Now we can cancel any terms in the denominator that have the same term in the numerator as
\n" ); document.write( "shown:
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "And the problem is reduced to:
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "This is now just an \"ordinary\" algebraic equation. Let's multiply out the all the terms to
\n" ); document.write( "get:
\n" ); document.write( ".
\n" ); document.write( "\"%282x%5E2%2Bx-6%29-%28x%5E2+-2x+%2B+1%29+=+%282x%5E2+-7x+%2B+5%29+%2B%28x%5E2+-+4%29\"
\n" ); document.write( ".
\n" ); document.write( "Remove the parentheses. If they are preceded by a + sign, just erase them. If they are
\n" ); document.write( "preceded by a minus sign, when you remove them, change the sign of all the terms inside. When
\n" ); document.write( "you remove the parentheses you get:
\n" ); document.write( ".
\n" ); document.write( "\"2x%5E2%2Bx-6-x%5E2+%2B2x-1+=+2x%5E2-7x%2B5%2Bx%5E2+-4\"
\n" ); document.write( ".
\n" ); document.write( "Grouping like terms on the left and right side results in:
\n" ); document.write( ".
\n" ); document.write( "\"2x%5E2+-+x%5E2+%2Bx+%2B+2x+-6+-1+=+2x%5E2+%2B+x%5E2+-+7x+%2B5+-4\"
\n" ); document.write( ".
\n" ); document.write( "Combining like terms gives you:
\n" ); document.write( ".
\n" ); document.write( "\"x%5E2+%2B+3x+-+7+=+3x%5E2+-7x+%2B1\"
\n" ); document.write( ".
\n" ); document.write( "Since this is going to be a quadratic equation, let's get it into standard form by moving
\n" ); document.write( "everything to the left side and just have a zero on the right side. Do this by subtracting
\n" ); document.write( "\"3x%5E2+-+7x+%2B+1\" from both sides. After grouping like terms on the left side, this
\n" ); document.write( "subtraction results in:
\n" ); document.write( ".
\n" ); document.write( "\"x%5E2+-+3x%5E2+%2B+3x+%2B+7x+-7+-+1+=+0\"
\n" ); document.write( ".
\n" ); document.write( "Combine like terms to get:
\n" ); document.write( ".
\n" ); document.write( "\"-2x%5E2+%2B+10x+-+8+=+0\"
\n" ); document.write( ".
\n" ); document.write( "Simplify by dividing both sides by -2:
\n" ); document.write( ".
\n" ); document.write( "\"x%5E2+-+5x+%2B4+=+0\"
\n" ); document.write( ".
\n" ); document.write( "This quadratic factors to:
\n" ); document.write( ".
\n" ); document.write( "\"%28x+-+4%29%2A%28x+-+1%29+=+0\"
\n" ); document.write( ".
\n" ); document.write( "and this equation will be true if either factor on the left side is zero. So one at a
\n" ); document.write( "time set the factors equal to zero and solve for x.
\n" ); document.write( ".
\n" ); document.write( "\"x+-+4+=+0\" Solve by adding 4 to both sides to get \"x+=+4\"
\n" ); document.write( ".
\n" ); document.write( "Next:
\n" ); document.write( ".
\n" ); document.write( "\"x+-+1+=+0\" Solve by adding 1 to both sides to get \"x+=+1\"
\n" ); document.write( ".
\n" ); document.write( "But this last solution has to be ignored. Why??? Go way back to the original problem and
\n" ); document.write( "note what happens if x = 1. If it does = 1 then a couple of the denominators become
\n" ); document.write( "zero, and division by zero is not allowed. Therefore, x = 1 is not a valid answer. The
\n" ); document.write( "only acceptable answer is x = 4.
\n" ); document.write( ".
\n" ); document.write( "You can check that by returning to the original problem and substituting 4 for x to see if
\n" ); document.write( "the left side of the equation still equals the right side. You should find that it does.
\n" ); document.write( ".
\n" ); document.write( "Hope this helps you to see your way through the problem.
\n" ); document.write( "
\n" ); document.write( "
\n" );