document.write( "Question 618242: I need help with this systems problem.\r
\n" ); document.write( "\n" ); document.write( "7x^2 + y^2 = 64
\n" ); document.write( "x + y = 4\r
\n" ); document.write( "\n" ); document.write( "Thanks \n" ); document.write( "

Algebra.Com's Answer #388794 by Maths68(1474) $\"\"$ $\"About$

You can put this solution on YOUR website!
$\"7x%5E2+%2B+y%5E2+=+64\"$ ...........(1)
\n" ); document.write( " $\"x+%2B+y+=+4\"$ .................(2)\r
\n" ); document.write( "\n" ); document.write( "Take (2)
\n" ); document.write( " $\"x+%2B+y+=+4\"$
\n" ); document.write( " $\"x=4-y\"$ .....................(3)\r
\n" ); document.write( "\n" ); document.write( "Put the value of x from (3) to (1)\r
\n" ); document.write( "\n" ); document.write( " $\"7x%5E2+%2B+y%5E2+=+64\"$ ...........(1)\r
\n" ); document.write( "\n" ); document.write( " $\"7%284-y%29%5E2+%2B+y%5E2+=+64\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"7%2816-8y%2By%5E2%29+%2B+y%5E2+=+64\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"112-56y%2B7y%5E2+%2B+y%5E2+=+64\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"112-56y%2B8y%5E2=+64\"$ \r
\n" ); document.write( "\n" ); document.write( " $\"8%2814-7y%2By%5E2%29=+64\"$
\n" ); document.write( "Divide by 8 both sides of the above equation
\n" ); document.write( " $\"8%2814-7y%2By%5E2%29%2F8=+64%2F8\"$
\n" ); document.write( " $\"cross%288%29%2814-7y%2By%5E2%29%2Fcross%288%29=+cross%2864%29%2Fcross%288%29\"$
\n" ); document.write( " $\"14-7y%2By%5E2=+8\"$
\n" ); document.write( " $\"14-7y%2By%5E2-8=0\"$
\n" ); document.write( " $\"y%5E2-7y%2B14-8=0\"$
\n" ); document.write( " $\"y%5E2-7y%2B6=0\"$
\n" ); document.write( "Now solve for y
\n" ); document.write( " $\"y%5E2-6y-y%2B6=0\"$
\n" ); document.write( " $\"y%28y-6%29-1%28y-6%29=0\"$
\n" ); document.write( " $\"%28y-6%29%28y-1%29=0\"$
\n" ); document.write( " $\"y-6=0\"$ Or $\"y-1=0\"$
\n" ); document.write( " $\"y=6\"$ Or $\"y=1\"$ \r
\n" ); document.write( "\n" ); document.write( "Put the values of y in (3)
\n" ); document.write( " $\"x=4-y\"$ .....................(3)
\n" ); document.write( "y=6
\n" ); document.write( " $\"x=4-6\"$
\n" ); document.write( " $\"x=-2\"$
\n" ); document.write( "y=1
\n" ); document.write( " $\"x=4-1\"$
\n" ); document.write( " $\"x=3\"$ \r
\n" ); document.write( "\n" ); document.write( "Solution set (x,y)=(-2,6),(3,1)\r
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\n" ); document.write( "\n" ); document.write( "Check
\n" ); document.write( "======
\n" ); document.write( "Put the values of x and y in either equation (1) or (2)\r
\n" ); document.write( "\n" ); document.write( "When(x,y)=(-2,6)\r
\n" ); document.write( "\n" ); document.write( " $\"7x%5E2+%2B+y%5E2+=+64\"$ ...........(1)
\n" ); document.write( " $\"7%28-2%29%5E2+%2B+%286%29%5E2+=+64\"$
\n" ); document.write( " $\"7%284%29+%2B+36+=+64\"$
\n" ); document.write( " $\"28+%2B+36+=+64\"$
\n" ); document.write( " $\"64=64\"$ \r
\n" ); document.write( "\n" ); document.write( "When(x,y)=(3,1)
\n" ); document.write( " $\"7x%5E2+%2B+y%5E2+=+64\"$ ...........(1)
\n" ); document.write( " $\"7%283%29%5E2+%2B+%281%29%5E2+=+64\"$
\n" ); document.write( " $\"7%289%29+%2B+1+=+64\"$
\n" ); document.write( " $\"63+%2B+1+=+64\"$
\n" ); document.write( " $\"64=64\"$ \r
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