Algebra.Com's Answer #59590 by jim_thompson5910(35256)  You can put this solution on YOUR website! Let r and s be x and y (they represent the same idea)\r \n" );
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document.write( "If you want to solve by using addition, then...\r \n" );
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document.write( " Solved by pluggable solver: Solving a System of Linear Equations by Elimination/Addition | \n" );
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document.write( " Lets start with the given system of linear equations \n" );
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document.write( " In order to solve for one variable, we must eliminate the other variable. So if we wanted to solve for y, we would have to eliminate x (or vice versa). \n" );
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document.write( " So lets eliminate x. In order to do that, we need to have both x coefficients that are equal but have opposite signs (for instance 2 and -2 are equal but have opposite signs). This way they will add to zero. \n" );
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document.write( " So to make the x coefficients equal but opposite, we need to multiply both x coefficients by some number to get them to an equal number. So if we wanted to get 3 and 1 to some equal number, we could try to get them to the LCM. \n" );
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document.write( " Since the LCM of 3 and 1 is 3, we need to multiply both sides of the top equation by 1 and multiply both sides of the bottom equation by -3 like this: \n" );
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document.write( " Multiply the top equation (both sides) by 1 \n" );
document.write( " Multiply the bottom equation (both sides) by -3 \n" );
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document.write( " So after multiplying we get this: \n" );
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document.write( " Notice how 3 and -3 add to zero (ie ) \n" );
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document.write( " Now add the equations together. In order to add 2 equations, group like terms and combine them \n" );
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document.write( " Notice the x coefficients add to zero and cancel out. This means we've eliminated x altogether. \n" );
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document.write( " So after adding and canceling out the x terms we're left with: \n" );
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document.write( " Divide both sides by to solve for y \n" );
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document.write( " Reduce \n" );
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document.write( " Now plug this answer into the top equation to solve for x \n" );
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document.write( " Plug in  \n" );
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document.write( " Multiply \n" );
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document.write( " Subtract from both sides \n" );
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document.write( " Combine the terms on the right side \n" );
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document.write( " Multiply both sides by . This will cancel out on the left side. \n" );
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document.write( " Multiply the terms on the right side \n" );
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document.write( " So our answer is \n" );
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document.write( " ,  \n" );
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document.write( " which also looks like \n" );
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document.write( " ( , ) \n" );
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document.write( " Notice if we graph the equations (if you need help with graphing, check out this solver) \n" );
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document.write( " we get \n" );
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document.write( " graph of (red) (green) (hint: you may have to solve for y to graph these) and the intersection of the lines (blue circle). \n" );
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document.write( " and we can see that the two equations intersect at ( , ). This verifies our answer. | \n" );
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document.write( "If you want to solve by using substitution, then...\r \n" );
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document.write( " Solved by pluggable solver: Solving a linear system of equations by subsitution | \n" );
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document.write( " Lets start with the given system of linear equations \n" );
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document.write( " Now in order to solve this system by using substitution, we need to solve (or isolate) one variable. I'm going to choose y. \n" );
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document.write( " Solve for y for the first equation \n" );
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document.write( " Subtract from both sides \n" );
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document.write( " Divide both sides by 5. \n" );
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document.write( " Which breaks down and reduces to \n" );
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document.write( " Now we've fully isolated y \n" );
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document.write( " Since y equals we can substitute the expression into y of the 2nd equation. This will eliminate y so we can solve for x. \n" );
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document.write( " Replace y with . Since this eliminates y, we can now solve for x. \n" );
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document.write( " Distribute 2 to  \n" );
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document.write( " Multiply \n" );
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document.write( " Reduce any fractions \n" );
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document.write( " Subtract from both sides \n" );
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document.write( " Make 13 into a fraction with a denominator of 5 \n" );
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document.write( " Combine the terms on the right side \n" );
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document.write( " Make 1 into a fraction with a denominator of 5 \n" );
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document.write( " Now combine the terms on the left side. \n" );
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document.write( " Multiply both sides by . This will cancel out and isolate x \n" );
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document.write( " So when we multiply and (and simplify) we get \n" );
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document.write( " <---------------------------------One answer \n" );
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document.write( " Now that we know that , lets substitute that in for x to solve for y \n" );
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document.write( " Plug in into the 2nd equation \n" );
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document.write( " Multiply \n" );
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document.write( " Add to both sides \n" );
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document.write( " Combine the terms on the right side \n" );
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document.write( " Multiply both sides by . This will cancel out 2 on the left side. \n" );
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document.write( " Multiply the terms on the right side \n" );
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document.write( " Reduce \n" );
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document.write( " So this is the other answer \n" );
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document.write( " <---------------------------------Other answer \n" );
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document.write( " So our solution is \n" );
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document.write( " and  \n" );
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document.write( " which can also look like \n" );
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document.write( " ( , ) \n" );
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document.write( " Notice if we graph the equations (if you need help with graphing, check out this solver) \n" );
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document.write( " we get \n" );
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document.write( " graph of (red) and (green) (hint: you may have to solve for y to graph these) intersecting at the blue circle. \n" );
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document.write( " and we can see that the two equations intersect at ( , ). This verifies our answer. \n" );
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document.write( " Check: \n" );
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document.write( " Plug in ( , ) into the system of equations \n" );
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document.write( " Let and . Now plug those values into the equation  \n" );
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document.write( " Plug in and  \n" );
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document.write( " Multiply \n" );
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document.write( " Add \n" );
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document.write( " Reduce. Since this equation is true the solution works. \n" );
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document.write( " So the solution ( , ) satisfies  \n" );
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document.write( " Let and . Now plug those values into the equation  \n" );
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document.write( " Plug in and  \n" );
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document.write( " Multiply \n" );
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document.write( " Add \n" );
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document.write( " Reduce. Since this equation is true the solution works. \n" );
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document.write( " So the solution ( , ) satisfies  \n" );
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document.write( " Since the solution ( , ) satisfies the system of equations \n" );
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document.write( " this verifies our answer. \n" );
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