document.write( "Question 616920: x+4y=-7
\n" ); document.write( "-4x+5y=28 \n" ); document.write( "

Algebra.Com's Answer #388002 by dragonwalker(73) $\"\"$ $\"About$

You can put this solution on YOUR website!
okay, so let us call x + 4y = -7 EQUATION ONE
\n" ); document.write( " and -4x + 5y = 28 EQUATION TWO\r
\n" ); document.write( "\n" ); document.write( "from equation one you can get:\r
\n" ); document.write( "\n" ); document.write( "x = -7 -4y (by moving the 4y to the other side (and when doing so changing the sign).\r
\n" ); document.write( "\n" ); document.write( "You can then multiply all values by four to give:\r
\n" ); document.write( "\n" ); document.write( "4x = -28 - 16y\r
\n" ); document.write( "\n" ); document.write( "Now change the signs for all values to get -4x:\r
\n" ); document.write( "\n" ); document.write( "-4x = 28 + 16y\r
\n" ); document.write( "\n" ); document.write( "you can then substitute this into equation 2:\r
\n" ); document.write( "\n" ); document.write( "(28 + 16y) + 5y = 28\r
\n" ); document.write( "\n" ); document.write( "16y + 5y = 28 - 28\r
\n" ); document.write( "\n" ); document.write( "21y = 0\r
\n" ); document.write( "\n" ); document.write( "so y = 0\r
\n" ); document.write( "\n" ); document.write( "Then use equation one with a value of y=0:\r
\n" ); document.write( "\n" ); document.write( "x = -7\r
\n" ); document.write( "\n" ); document.write( "so x= -7 and y=0 \n" ); document.write( "

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