document.write( "Question 320219: Solve by substitution method\r
\n" ); document.write( "\n" ); document.write( "7x+8y=36
\n" ); document.write( "X=60-8y\r
\n" ); document.write( "\n" ); document.write( "Thank you \n" ); document.write( "
Algebra.Com's Answer #229338 by Sunny Day(15)\"\" \"About 
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7x+8y=36 ----------- (1)\r
\n" ); document.write( "\n" ); document.write( "x=60-8y ------------(2)\r
\n" ); document.write( "\n" ); document.write( "(2) gives an equation for x and hence we can substitute this value in place of x in (1)\r
\n" ); document.write( "\n" ); document.write( "So (1) becomes 7(60 - 8y) + 8y = 36 which is an equation in one variable. \r
\n" ); document.write( "\n" ); document.write( "Simplifying, 7X60 - 7X8y +8y = 36\r
\n" ); document.write( "\n" ); document.write( " 420 - 56y + 8y =36
\n" ); document.write( " -48y =36 - 420
\n" ); document.write( " -48y = -384
\n" ); document.write( " y = -384/-48
\n" ); document.write( " i.e y = 8\r
\n" ); document.write( "\n" ); document.write( "So x = 60 - 8X8 (putting y=8 in (2))\r
\n" ); document.write( "\n" ); document.write( " x = 60 - 64 = -4\r
\n" ); document.write( "\n" ); document.write( "Hence x = -4 and y = 8 is the required solution
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