document.write( "Question 638414: Rational Equations. Solve the equation.\r
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document.write( "(2x-9)/(x-7)+x/2=5/(x-7) \n" );
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Algebra.Com's Answer #402177 by josh_jordan(263)![]() ![]() You can put this solution on YOUR website! to solve for x, you will first need to find the LCD of the fractions involved. Let's look at the denominators: x - 7, 2, x - 7. The LCD of these fractions is 2(x - 7). We will then multiply each fraction by \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since we can cancel out the same terms from both the numerator and denominator of each fraction, we are left with:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "If we subtract the 10 on the right side of the equal sign, from both sides, we are left with a quadratic equation:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Let's see if we can solve this equation by factoring. We need to find out if any numbers that will multiply together and produce -28, can be added together to equal -3: 4 x -7= 28 and when we add 4 to -7, we get -3. So, turning this equation into factors, we get (x - 7)(x + 4) = 0, which means x = 7 and/or x = -4. Since we are unsure if either or both will work, we will have to substitute 7 and -4 for x in our original equation. Uh oh. Look at the first fraction in our equation. The denominator is x - 7. If we plug our 7 in for x, our denominator will equal 0. Denominators cannot equal 0, therefore, we know right away that 7 cannot be one of our solutions.\r \n" ); document.write( "\n" ); document.write( "Now, let's try -4:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The LCD of our remaining fractions is 11, so we would multiply 11 by each of our fractions by 11, which would leave us with the following:\r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "since both sides of the equal sign are the same, we know that -4 is a solution.\r \n" ); document.write( "\n" ); document.write( "Final Answer: x = -4 \n" ); document.write( " \n" ); document.write( " |