document.write( "Question 269623: Barry is helping his friend understand how to solvesystems of equations. He wants to give her a problem to practice. He wants to give her a problem that has two lines that intersect at the point (-3,7). Help him by writing a system of equations that will have (-3,7) as a solution and demonstrate how to solve it. \n" ); document.write( "
Algebra.Com's Answer #197596 by stanbon(75887)\"\" \"About 
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writing a system of equations that will have (-3,7) as a solution and demonstrate how to solve it.
\n" ); document.write( "---------------
\n" ); document.write( "x = -3 and y = 7
\n" ); document.write( "3x = -9 and 4y = 28
\n" ); document.write( "Add to get the 1st equation:
\n" ); document.write( "3x + 4y = 19
\n" ); document.write( "=============================
\n" ); document.write( "x = -3 and y = 7
\n" ); document.write( "-2x = 6 and 2y = 14
\n" ); document.write( "Add to get:
\n" ); document.write( "-2x + 2y = 20
\n" ); document.write( "-x + y = 10
\n" ); document.write( "===========================
\n" ); document.write( "System:
\n" ); document.write( "3x + 4y = 19
\n" ); document.write( "-x + y = 10
\n" ); document.write( "-------------------
\n" ); document.write( "Solve by substitution:
\n" ); document.write( "y = x + 10
\n" ); document.write( "3x + 4(x+10) = 19
\n" ); document.write( "7x + 40 = 19
\n" ); document.write( "7x = -21
\n" ); document.write( "x = -3
\n" ); document.write( "---
\n" ); document.write( "Since y = x+10
\n" ); document.write( "y = -3+10 = 7
\n" ); document.write( "=====================
\n" ); document.write( "solution: x = -3, y = 7
\n" ); document.write( "===========================
\n" ); document.write( "cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
\n" );