document.write( "Question 822059: given the equation 3x+9y=-8, write a second linear equation to create a system that:
\n" ); document.write( "• has exactly one solution. Explain your reasoning
\n" ); document.write( "• has no solution. Explain your reasoning
\n" ); document.write( "• has infinitely many solutions. Explain your reasoning\r
\n" ); document.write( "\n" ); document.write( "• interpret the meaning of the solution, if it exist, in the context of the graph of the following system if equations.
\n" ); document.write( "-5x+2y=10
\n" ); document.write( "10x-4y=20
\n" ); document.write( "

Algebra.Com's Answer #494565 by TimothyLamb(4379)\"\" \"About 
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\n" ); document.write( "original, standard form: ax + by = c
\n" ); document.write( "3x + 9y = -8
\n" ); document.write( "slope = -a/b = -3/9 = -1/3
\n" ); document.write( "y-intercept = c/b = -8/9
\n" ); document.write( "---
\n" ); document.write( "write second linear equation where the system has only one solution:
\n" ); document.write( "3x + 9y = -8
\n" ); document.write( "9x - 3y = -8
\n" ); document.write( "slope = -a/b = -9/-3 = 3
\n" ); document.write( "y-intercept = c/b = -8/-3 = 8/3
\n" ); document.write( "reason: slopes are negative reciprocal, so the lines are perpendicular and must have a unique solution, in this case the solution is:
\n" ); document.write( "x= -1.06666667
\n" ); document.write( "y= -0.533333333
\n" ); document.write( "---
\n" ); document.write( "write second linear equation where the system has no solution:
\n" ); document.write( "3x + 9y = -8
\n" ); document.write( "3x + 9y = 0
\n" ); document.write( "slope = -a/b = -3/9 = -1/3
\n" ); document.write( "y-intercept = c/b = 0/9 = 0
\n" ); document.write( "reason: slopes are equal, so the lines are parallel, but they have distinct y-intercepts so the lines have no common solution because they never intersect
\n" ); document.write( "---
\n" ); document.write( "write second linear equation where the system has infinitely many solutions:
\n" ); document.write( "3x + 9y = -8
\n" ); document.write( "6x + 18y = -16
\n" ); document.write( "slope = -a/b = -6/18 = -1/3
\n" ); document.write( "y-intercept = c/b = -16/18 = -8/9
\n" ); document.write( "reason: slopes are equal, so the lines are parallel, and their y-intercepts are equal, so the lines are coincident, hence have an infinite number of solutions
\n" ); document.write( "---
\n" ); document.write( "-5x + 2y = 10
\n" ); document.write( "10x - 4y = 20
\n" ); document.write( "the lines have equal slopes (5/2), so the lines are parallel, but different y-intercepts (5) and (-5), so they do not intercept and hence have no common solution
\n" ); document.write( "---
\n" ); document.write( "Solve and graph linear equations:
\n" ); document.write( "https://sooeet.com/math/linear-equation-solver.php
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\n" ); document.write( "Solve quadratic equations, quadratic formula:
\n" ); document.write( "https://sooeet.com/math/quadratic-formula-solver.php
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\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
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