document.write( "Question 76095: I really need the solution\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "(5/y-3) - (30 /y^2-9) = 1
\n" ); document.write( "

Algebra.Com's Answer #54632 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
\"5%2F%28y-3%29+-+30+%2F%28y%5E2-9%29+=+1\"
\n" ); document.write( ".
\n" ); document.write( "The denominator \"y%5E2-9\" is the difference of two squares. The rule that applies to
\n" ); document.write( "factoring the difference between two squares is:
\n" ); document.write( ".
\n" ); document.write( "\"a%5E2+-+b%5E2+=+%28a+%2B+b%29%2A%28a+-+b%29\"
\n" ); document.write( ".
\n" ); document.write( "Applying this rule to \"y%5E2+-+9\" results in:
\n" ); document.write( ".
\n" ); document.write( "\"y%5E2+-+9=+%28y+%2B+3%29%2A%28y+-+3%29\"
\n" ); document.write( ".
\n" ); document.write( "Substituting this into the equation changes the equation to:
\n" ); document.write( ".
\n" ); document.write( "\"5%2F%28y-3%29+-+30%2F%28%28y%2B3%29%2A%28y-3%29%29+=+1\"
\n" ); document.write( ".
\n" ); document.write( "You can get all the terms over the common denominator of \"%28y+%2B+3%29%2A%28y+-+3%29\". Multiply the
\n" ); document.write( "first term by \"%28y%2B3%29%2F%28y%2B3%29\" which is the same as multiplying the first term by 1 because
\n" ); document.write( "the numerator of this multiplier is the same as the denominator. When you do this
\n" ); document.write( "multiplication the equation becomes:
\n" ); document.write( ".
\n" ); document.write( "\"5%28y%2B3%29%2F%28%28y%2B3%29%2A%28y-3%29%29+-+30%2F%28%28y%2B3%29%2A%28y-3%29%29+=+1\"
\n" ); document.write( ".
\n" ); document.write( "Then multiply the 1 on the right side by \"%28%28y%2B3%29%2A%28y-3%29%29%2F%28%28y%2B3%29%2A%28y-3%29%29\". This multiplication
\n" ); document.write( "results in:
\n" ); document.write( "
\n" ); document.write( ".
\n" ); document.write( "Now you can multiply the entire equation (both sides, all terms) by the common denominator
\n" ); document.write( "\"+%28%28y%2B3%29%2A%28y-3%29%29\" and after that multiplication you are left with only the numerators
\n" ); document.write( "of all the terms in the equation. The result is:
\n" ); document.write( ".
\n" ); document.write( "\"5%2A%28y%2B3%29+-+30+=+%28y+%2B+3%29%2A%28y+-+3%29\"
\n" ); document.write( ".
\n" ); document.write( "Multiply where called for and the equation becomes:
\n" ); document.write( ".
\n" ); document.write( "\"5y+%2B+15+-+30+=+y%5E2+-+9\"
\n" ); document.write( ".
\n" ); document.write( "Subtract \"y%5E2-9\" from both sides to get:
\n" ); document.write( ".
\n" ); document.write( "\"5y+%2B+15+-+30+-+y%5E2+%2B+9+=+0\"
\n" ); document.write( ".
\n" ); document.write( "Rearrange terms in descending powers of y:
\n" ); document.write( ".
\n" ); document.write( "\"-y%5E2+%2B+5y+%2B+15+-+30+%2B+9+=+0\"
\n" ); document.write( ".
\n" ); document.write( "Combine the constants:
\n" ); document.write( ".
\n" ); document.write( "\"-y%5E2+%2B+5y+-+6+=+0\"
\n" ); document.write( ".
\n" ); document.write( "Multiply the entire equation (both sides and all terms) by -1 to get:
\n" ); document.write( ".
\n" ); document.write( "\"y%5E2+-+5y+%2B+6+=+0\"
\n" ); document.write( ".
\n" ); document.write( "This factors to:
\n" ); document.write( ".
\n" ); document.write( "\"%28y-3%29%2A%28y-2%29+=+0\"
\n" ); document.write( ".
\n" ); document.write( "If either of the factors equals zero, then the equation is true because a multiplication
\n" ); document.write( "by zero on the left side, makes the entire left side equal to the zero on the right side.
\n" ); document.write( "Find the solutions for y by setting each of the factors equal to zero and solving for
\n" ); document.write( "y ...
\n" ); document.write( ".
\n" ); document.write( "y - 2 = 0 <---- add 2 to both sides
\n" ); document.write( ".
\n" ); document.write( "y = +2 <--- one answer for y
\n" ); document.write( ".
\n" ); document.write( "y - 3 = 0 <--- add 3 to both sides
\n" ); document.write( ".
\n" ); document.write( "y = +3 <--- the second answer for y
\n" ); document.write( ".
\n" ); document.write( "But the second answer [y = +3] is not permitted because this would cause a division by
\n" ); document.write( "zero in the second term of the original equation ... the denominator of the second term
\n" ); document.write( "is \"y%5E2+-+9\" and it is equal to \"%28y%2B3%29%2A%28y-3%29\" and if y is allowed to equal
\n" ); document.write( "+3 then one of the factors in the denominator is zero ... and division by zero is not
\n" ); document.write( "permitted.
\n" ); document.write( ".
\n" ); document.write( "So there you are ... the answer to the equation is y = +2.
\n" ); document.write( ".
\n" ); document.write( "Hope this helps you to understand the problem a little better.
\n" ); document.write( "
\n" );