document.write( "Question 942146: Hi,\r
\n" ); document.write( "\n" ); document.write( "Can you help me with this exercise,please\r
\n" ); document.write( "\n" ); document.write( "It says the following\r
\n" ); document.write( "\n" ); document.write( "z1=-5+4i
\n" ); document.write( "z2=K+6i\r
\n" ); document.write( "\n" ); document.write( "Find k such that:\r
\n" ); document.write( "\n" ); document.write( "(z1+z2)/z1+i\r
\n" ); document.write( "\n" ); document.write( "I found the complex conjugate of z1+i which is :-5-5i and then I multiplied top and bottom with this conjugate and I've got a really big fraction which I don't know what to do with it.Can you plese help me with this \r
\n" ); document.write( "\n" ); document.write( "Thank you so much
\n" ); document.write( " \n" ); document.write( "

Algebra.Com's Answer #574350 by rothauserc(4718) $\"\"$ $\"About$

You can put this solution on YOUR website!
note that i^2 = -1
\n" ); document.write( "first determine the conjugate
\n" ); document.write( "z1 + i = -5 +4i +i = -5 +5i
\n" ); document.write( "conjugate is (-5 -5i)
\n" ); document.write( "z1 + z2 = -5+4i + K+6i = k +10i -5
\n" ); document.write( "multiply numerator and denominator by the conjugate
\n" ); document.write( "note that we assume k is real
\n" ); document.write( "((k+10i-5)*(-5-5i)) / ((-5+5i)*(-5-5i))
\n" ); document.write( "note that ((-5+5i)*(-5-5i)) = 25-25i^2 = 50
\n" ); document.write( "(-5ki-5k-25i+75) / 50
\n" ); document.write( "divide numerator and denominator by 5
\n" ); document.write( "-ki-k-5i+15 /10
\n" ); document.write( "i(-k-5)-k+15 / 10
\n" ); document.write( "i(-k/10 -1/2)-(k/10)+(3/2)\r
\n" ); document.write( "
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