document.write( "Question 640197: Solve for X: √(X+5)=X-1
\n" ); document.write( "(√(X+5))^2=(X-1)^2
\n" ); document.write( "X+5=X^2-2X+1
\n" ); document.write( "X^2-3X-4=0
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Algebra.Com's Answer #403058 by josh_jordan(263)\"\" \"About 
You can put this solution on YOUR website!
Almost there! :) Last line says: \"x%5E2+-+3x+-+4+=+0\"\r
\n" ); document.write( "\n" ); document.write( "We can solve for x in 3 different ways: factoring, completing the square, or using the quadratic formula. The easiest of these ways is factoring, so let's see if we can factor this equation.\r
\n" ); document.write( "\n" ); document.write( "Let's look at the number at the end of the left side of the equal sign: -4
\n" ); document.write( "Now let's look at the middle number/variable: -3.
\n" ); document.write( "For us to be able to solve by factoring, we need to have 2 numbers that multiply together to equal -4 AND can be added together to equal -3. Let's look at the products of -4:\r
\n" ); document.write( "\n" ); document.write( "-1 x 4 = -4
\n" ); document.write( " 1 x -4 = -4
\n" ); document.write( " 2 x -2 = -4
\n" ); document.write( "-2 x 2 = -4\r
\n" ); document.write( "\n" ); document.write( "Now, let's add each of these products to see if they equal -3:\r
\n" ); document.write( "\n" ); document.write( "-1 + 4 = 3
\n" ); document.write( " 1 + -4 = -3\r
\n" ); document.write( "\n" ); document.write( "We can stop right there, because 1 + -4 = -3\r
\n" ); document.write( "\n" ); document.write( "So, \"x%5E2+-+3x+-+4+=+0\" can be re-written as
\n" ); document.write( "\"%28x+%2B+1%29%28x+-+4%29+=+0\"\r
\n" ); document.write( "\n" ); document.write( "\"x+%2B+1+=+0\" = \"x+=+-1\"
\n" ); document.write( "AND
\n" ); document.write( "\"x+-+4+=+0\" = \"x+=+4\"\r
\n" ); document.write( "\n" ); document.write( "To find out if both of these numbers are solutions, we will substitute x in our original equation for each of our possible solutions:\r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28x%2B5%29+=+x+-+1\" = \"sqrt%28-1%2B5%29+=+-1+%2B+-1\" =
\n" ); document.write( "\"sqrt%284%29+=+-2\" =
\n" ); document.write( "\"2+=+-2\"\r
\n" ); document.write( "\n" ); document.write( "Since 2 does NOT equal -2, we know that -1 is NOT a solution\r
\n" ); document.write( "\n" ); document.write( "Now let's try 4:\r
\n" ); document.write( "\n" ); document.write( "\"sqrt%28x%2B5%29+=+x+-+1\" = \"sqrt%284%2B5%29+=+4+-+1\" =
\n" ); document.write( "\"sqrt%289%29+=+3\" =
\n" ); document.write( "\"3+=+3\"\r
\n" ); document.write( "\n" ); document.write( "Since both sides of the equal sign are the same, 4 IS a solution. \r
\n" ); document.write( "\n" ); document.write( "FINAL ANSWER: x = 4
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