document.write( "Question 106725: z^2+5z-14=0 \n" ); document.write( "
Algebra.Com's Answer #77664 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
\n" ); document.write( "\n" ); document.write( " \n" ); document.write( "\n" ); document.write( "
Solved by pluggable solver: Quadratic Formula
Let's use the quadratic formula to solve for z:

\n" ); document.write( "\n" ); document.write( "
\n" ); document.write( " Starting with the general quadratic
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"az%5E2%2Bbz%2Bc=0\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " the general solution using the quadratic equation is:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-b+%2B-+sqrt%28+b%5E2-4%2Aa%2Ac+%29%29%2F%282%2Aa%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So lets solve \"z%5E2%2B5%2Az-14=0\" ( notice \"a=1\", \"b=5\", and \"c=-14\")
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+sqrt%28+%285%29%5E2-4%2A1%2A-14+%29%29%2F%282%2A1%29\" Plug in a=1, b=5, and c=-14
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+sqrt%28+25-4%2A1%2A-14+%29%29%2F%282%2A1%29\" Square 5 to get 25
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+sqrt%28+25%2B56+%29%29%2F%282%2A1%29\" Multiply \"-4%2A-14%2A1\" to get \"56\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+sqrt%28+81+%29%29%2F%282%2A1%29\" Combine like terms in the radicand (everything under the square root)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+9%29%2F%282%2A1%29\" Simplify the square root (note: If you need help with simplifying the square root, check out this solver)
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B-+9%29%2F2\" Multiply 2 and 1 to get 2
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So now the expression breaks down into two parts
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z+=+%28-5+%2B+9%29%2F2\" or \"z+=+%28-5+-+9%29%2F2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Lets look at the first part:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"x=%28-5+%2B+9%29%2F2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z=4%2F2\" Add the terms in the numerator
\n" ); document.write( "
\n" ); document.write( " \"z=2\" Divide
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So one answer is
\n" ); document.write( "
\n" ); document.write( " \"z=2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " Now lets look at the second part:
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"x=%28-5+-+9%29%2F2\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " \"z=-14%2F2\" Subtract the terms in the numerator
\n" ); document.write( "
\n" ); document.write( " \"z=-7\" Divide
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So another answer is
\n" ); document.write( "
\n" ); document.write( " \"z=-7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( " So our solutions are:
\n" ); document.write( "
\n" ); document.write( " \"z=2\" or \"z=-7\"
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "
\n" );