document.write( "Question 286132: I do not know how to solve system equations using substitions with fractions. Do i multiply by a common denominator?
\n" ); document.write( "here is an example if you could solve it step by step for me:
\n" ); document.write( "7x-y=10
\n" ); document.write( "x=1/3y-2\r
\n" ); document.write( "\n" ); document.write( "i know the answer (4,18) but not how to get there. if you can help it would be greatly appreciated thank you. \n" ); document.write( "

Algebra.Com's Answer #207473 by ptaylor(2198) $\"\"$ $\"About$

You can put this solution on YOUR website!
I'm confused. In the second equation is it 1/(3y) or (1/3)y. I will assume that it's the latter, so:\r
\n" ); document.write( "\n" ); document.write( "7x-y=10-------------------------eq1
\n" ); document.write( "x=(1/3)y-2---------------------eq2\r
\n" ); document.write( "\n" ); document.write( "If we get rid of the fraction in eq2, then you may not have to worry about it, so:
\n" ); document.write( "Multiply each term in eq2 by 3 and we get
\n" ); document.write( "3x=y-6 add 6 to each side
\n" ); document.write( "3x+6=y----eq2a
\n" ); document.write( "now substitute 3x+6 for y in eq 1
\n" ); document.write( "7x-(3x+6)=10
\n" ); document.write( "7x-3x-6=10 add 6 to each side
\n" ); document.write( "7x-3x-6+6=10+6 collect like terms
\n" ); document.write( "4x=16
\n" ); document.write( "x=4
\n" ); document.write( "substitute x=4 into eq2a and we get:
\n" ); document.write( "3*4+6=y
\n" ); document.write( "y=18\r
\n" ); document.write( "\n" ); document.write( "Hope this helps---ptaylor \n" ); document.write( "

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