document.write( "Question 175701: how do I solve the system of equations 3r-4s+0 and 2r+5s=23? \n" ); document.write( "
Algebra.Com's Answer #130805 by Mathtut(3670)![]() ![]() ![]() You can put this solution on YOUR website! there are a few ways but lets use elimination method which means you want to manipulate the equation so the point where one set of terms are eliminated \n" ); document.write( ": \n" ); document.write( "I assumed that the +0 in eq 1 was really =0 \n" ); document.write( ": \n" ); document.write( "3r-4s=0......eq 1 \n" ); document.write( "2r+5s=23.....eq 2 \n" ); document.write( ": \n" ); document.write( "multiply all terms in eq 1 by 5 and all the terms in eq 2 by 4 and then add the 2 equations together. I will do the math then rewrite the equations next to one another so you can see what is taking place. \n" ); document.write( ": \n" ); document.write( "5(3r-4s=0)---->15r-20s=0 (revised eq 1) \n" ); document.write( "4(2r+5s=23)---->8r+20s=92 (revised eq 2) \n" ); document.write( ": \n" ); document.write( "can you see what happens to the s terms when we add the two equations together. They are eliminated because -20s+20s=0. We are left with 15r+8r=92+0 \n" ); document.write( ": \n" ); document.write( "23r=92 \n" ); document.write( ": \n" ); document.write( " \n" ); document.write( ": \n" ); document.write( "now take r's found value and plug it back into any equation. I am going to use eq 1 \n" ); document.write( ": \n" ); document.write( "3(4)-4s=0--->12-4s=0--->4s=12 \n" ); document.write( ": \n" ); document.write( " |