document.write( "Question 177920: Algebraically find the EXACT ROOTS in simplest form for: x/-7=(x+1)/(x-11) \n" ); document.write( "
Algebra.Com's Answer #132959 by gonzo(654)\"\" \"About 
You can put this solution on YOUR website!
this equation doesn't have any roots.
\n" ); document.write( "when you solve for the roots you get a complex number.
\n" ); document.write( "complex number means there are no roots.
\n" ); document.write( "here's how i did it.
\n" ); document.write( "your equation is:
\n" ); document.write( "\"%28x%2F-7%29+=+%28x%2B1%29%2F%28x-11%29\"
\n" ); document.write( "muiltiply both sides by -7 to get:
\n" ); document.write( "\"x+=+-7+%2A+%28x%2B1%29%2F%28x-11%29\"
\n" ); document.write( "multiply both sides by (x-11) to get:
\n" ); document.write( "\"x+%2A+%28x-11%29+=+-7+%2A+%28x%2B1%29\"
\n" ); document.write( "simplify to get:
\n" ); document.write( "\"x%5E2+-+11x+=+-7x+-+7\"
\n" ); document.write( "add 7x to both sides to get:
\n" ); document.write( "\"x%5E2+-+11x+%2B+7x+=+-7\"
\n" ); document.write( "add 7 to both sides to get\":
\n" ); document.write( "\"x%5E2+-+11x+%2B+7x+%2B+7+=+0\"
\n" ); document.write( "simplify to get:
\n" ); document.write( "\"x%5E2+-+4x+%2B+7+=+0\"
\n" ); document.write( "---
\n" ); document.write( "you can solve this using the quadratic formula or completing the squares.
\n" ); document.write( "either way will get you the same answer.
\n" ); document.write( "i'll use the quadratic formula first:
\n" ); document.write( "a = 1 = coefficient of the x^2 term.
\n" ); document.write( "b = -4 = coefficient of the x term.
\n" ); document.write( "c = 7 = constant term.
\n" ); document.write( "quadratic formula is:
\n" ); document.write( "\"x+=+%28-b+%2B-+sqrt%28b%5E2-4ac%29%2F%282a%29%29\"
\n" ); document.write( "substituting values for a,b,c gets:
\n" ); document.write( "\"x+=+%28-%28-4%29+%2B-+sqrt%28%28-4%29%5E2+-+4%2A7%2A1%29%2F%282%2A1%29%29\"
\n" ); document.write( "this becomes:
\n" ); document.write( "\"x+=+4+%2B-+sqrt%2816+-+28%29%2F%282%29\"
\n" ); document.write( "which becomes:
\n" ); document.write( "\"x+=+4+%2B-+sqrt%28-12%29%2F%282%29\"
\n" ); document.write( "which becomes:
\n" ); document.write( "\"x+=+4+%2B-+sqrt%28-3%2A2%2A2%29+%2F+%282%29+\"
\n" ); document.write( "which becomes:
\n" ); document.write( "\"+x+=+4+%2B-+2%2Asqrt%28-3%29%2F%282%29\"
\n" ); document.write( "which becomes:
\n" ); document.write( "\"+x+=+2+%2B-+sqrt%28-3%29\"
\n" ); document.write( "---
\n" ); document.write( "you can also solve this by completing the squares as follows:
\n" ); document.write( "your equation after manipulating it is:
\n" ); document.write( "\"x%5E2+-+4x+%2B+7+=+0\"
\n" ); document.write( "this is the same place where we solved it using the quadratic formula.
\n" ); document.write( "this time, however, we will complete the squares.
\n" ); document.write( "subtract 7 from both sides to get:
\n" ); document.write( "\"x%5E2+-+4x+=+-7\"
\n" ); document.write( "\"x%5E2+-+4x+=+%28x-2%29%5E2+-+4\"
\n" ); document.write( "your equation becomes:
\n" ); document.write( "\"%28x-2%29%5E2+-+4+=+-7\"
\n" ); document.write( "you add 4 to both sides to get:
\n" ); document.write( "\"%28x-2%29%5E2+=+-3\"
\n" ); document.write( "you take the square root of both sides to get:
\n" ); document.write( "\"x-2\" = +/- \"sqrt%28-3%29\"
\n" ); document.write( "you add 2 to both sides to get:
\n" ); document.write( "\"x+=+2+%2B-+sqrt%28-3%29\"
\n" ); document.write( "---
\n" ); document.write( "since the value of x is a complex number, this means that there are no roots to the equation.
\n" ); document.write( "since the roots are when the equation crosses the x-axis, this means that this equation does not cross the x-axis.
\n" ); document.write( "a graph of \"x%5E2-4x%2B7\" is shown below:
\n" ); document.write( "\"graph%28800%2C800%2C-20%2C20%2C-20%2C20%2Cx%5E2-4x%2B7%29\"\r
\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( "
\n" );