document.write( "Question 826630: I am supposed to solve by substitution. My equations are \r
\n" ); document.write( "\n" ); document.write( "3/4x + 1/2y = -7/12
\n" ); document.write( "and
\n" ); document.write( "x - y = -4/3\r
\n" ); document.write( "\n" ); document.write( "I have tried getting x alone on the first question but can't get the right answer \n" ); document.write( "
Algebra.Com's Answer #498185 by TimothyLamb(4379)\"\" \"About 
You can put this solution on YOUR website!
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\n" ); document.write( "3/4x + 1/2y = -7/12
\n" ); document.write( "x - y = -4/3
\n" ); document.write( "---
\n" ); document.write( "put the system of linear equations into standard form:
\n" ); document.write( "---
\n" ); document.write( "( 3/4x + 1/2y = -7/12 ) 12
\n" ); document.write( "( x - y = -4/3 ) 3
\n" ); document.write( "---
\n" ); document.write( "9x + 6y = -7
\n" ); document.write( "3x - 3y = -4
\n" ); document.write( "---
\n" ); document.write( "copy and paste the above linear system in standard form into this matrix-method solver:
\n" ); document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php
\n" ); document.write( "---
\n" ); document.write( "solution by matrix method:
\n" ); document.write( "x = -1
\n" ); document.write( "y = 0.33333333 = 1/3
\n" ); document.write( "---
\n" ); document.write( "system matrix
\n" ); document.write( "9 6
\n" ); document.write( "3 -3
\n" ); document.write( "---
\n" ); document.write( "inverse of system matrix
\n" ); document.write( "0.066666667 0.13333333
\n" ); document.write( "0.066666667 -0.2
\n" ); document.write( "---
\n" ); document.write( "determinant of system matrix = -45
\n" ); document.write( "---
\n" ); document.write( "now solve by substitution method:
\n" ); document.write( "---
\n" ); document.write( "6y = -7 - 9x
\n" ); document.write( "y = -(7/6) - (9/6)x
\n" ); document.write( "---
\n" ); document.write( "substitute into:
\n" ); document.write( "3x - 3y = -4
\n" ); document.write( "3x - 3( -(7/6) - (9/6)x ) = -4
\n" ); document.write( "3x + (7/2) + (9/2)x = -4
\n" ); document.write( "3x + (9/2)x = -4 - (7/2)
\n" ); document.write( "(6/2)x + (9/2)x = -(8/2) - (7/2)
\n" ); document.write( "( (6/2)x + (9/2)x = -(8/2) - (7/2) ) 2
\n" ); document.write( "15x = -15
\n" ); document.write( "---
\n" ); document.write( "x = -1
\n" ); document.write( "---
\n" ); document.write( "y = -(7/6) - (9/6)x
\n" ); document.write( "y = -(7/6) - (9/6)(-1)
\n" ); document.write( "y = -(7/6) + (9/6)
\n" ); document.write( "y = 2/6
\n" ); document.write( "---
\n" ); document.write( "y = 1/3
\n" ); document.write( "---
\n" ); document.write( "solution by substitution method:
\n" ); document.write( "x = -1
\n" ); document.write( "y = 0.33333333 = 1/3
\n" ); document.write( "---
\n" ); document.write( "both methods agree!
\n" ); document.write( "---
\n" ); document.write( "Solve and graph linear equations:
\n" ); document.write( "https://sooeet.com/math/linear-equation-solver.php
\n" ); document.write( "---
\n" ); document.write( "Solve quadratic equations, quadratic formula:
\n" ); document.write( "https://sooeet.com/math/quadratic-formula-solver.php
\n" ); document.write( "---
\n" ); document.write( "Solve systems of linear equations up to 6-equations 6-variables:
\n" ); document.write( "https://sooeet.com/math/system-of-linear-equations-solver.php \n" ); document.write( "
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