document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=66298>Question 66298</A>: <I><SPAN STYLE=\"word-break: break-all;\"> 1. 2x=y-1           <BR>\n" );
document.write( "   y=3x\r<BR>\n" );
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document.write( "2. x=-y<BR>\n" );
document.write( "   2x+y=-2\r<BR>\n" );
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document.write( "3. 2x+2y=4<BR>\n" );
document.write( "   x=10-3y\r<BR>\n" );
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document.write( "4. y=7-x<BR>\n" );
document.write( "   2x+3y=-1\r<BR>\n" );
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document.write( "                   <BR>\n" );
document.write( "Solve by substitution. Check your answers. <BR>\n" );
document.write( "I am new to Algebra 1 having trouble solving these problems. <BR>\n" );
document.write( "Can you help!!!! Thanks<BR>\n" );
document.write( "ISBN: 0-03-070039-6 pg 756 1-4 plus #6 ch 7.2 </SPAN>\n" );
document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #47025 by </B><A HREF=/tutors/aboutme.mpl?userid=funmath><B>funmath(2933)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=funmath><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/images/nopicture.jpg><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=47025\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> 1. <BR>\n" );
document.write( "E1) 2x=y-1           <BR>\n" );
document.write( "E2)   y=3x<BR>\n" );
document.write( "Let y=3x in E1 and solve for x:<BR>\n" );
document.write( "2x=3x-1<BR>\n" );
document.write( "2x-3x=3x-3x-1<BR>\n" );
document.write( "-x=-1<BR>\n" );
document.write( "-(-x)=-(-1)<BR>\n" );
document.write( "x=1<BR>\n" );
document.write( "Now let x=1 in E2 and solve for y:<BR>\n" );
document.write( "y=3(1)<BR>\n" );
document.write( "y=3<BR>\n" );
document.write( "The answer (x,y)=(1,3)<BR>\n" );
document.write( "To check your answer, let x=1 and y=3 in both equations and see if they balance:<BR>\n" );
document.write( "E1) 2(1)=(3)-1 <BR>\n" );
document.write( "2=2 We're right for the 1st equation.<BR>\n" );
document.write( "E2) (3)=3(1)<BR>\n" );
document.write( "3=3 We're right for both equations.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "2.<BR>\n" );
document.write( "E1) x=-y<BR>\n" );
document.write( "E2)   2x+y=-2<BR>\n" );
document.write( "Let x=-y in E2 and solve for y:<BR>\n" );
document.write( "2(-y)+y=-2<BR>\n" );
document.write( "-2y+y=-2<BR>\n" );
document.write( "-y=-2<BR>\n" );
document.write( "-(-y)=-(-2)<BR>\n" );
document.write( "y=2<BR>\n" );
document.write( "Now let y=2 in E1 and solve for x:<BR>\n" );
document.write( "x=-(2)<BR>\n" );
document.write( "x=-2<BR>\n" );
document.write( "The answer (x,y)=(-2,2)<BR>\n" );
document.write( "Check:<BR>\n" );
document.write( "E1) (-2)=-(2)<BR>\n" );
document.write( "-2=-2  So far so good.<BR>\n" );
document.write( "E2)  2(-2)+(2)=-2<BR>\n" );
document.write( "-4+2=-2<BR>\n" );
document.write( "-2=-2  We're really good.<BR>\n" );
document.write( ":<BR>\n" );
document.write( "3. <BR>\n" );
document.write( "E1) 2x+2y=4<BR>\n" );
document.write( "E2)   x=10-3y<BR>\n" );
document.write( "Let x=10-3y in E1 and solve for y:<BR>\n" );
document.write( "2(10-3y)+2y=4<BR>\n" );
document.write( "20-6y+2y=4<BR>\n" );
document.write( "20-4y=4<BR>\n" );
document.write( "20-20-4y=4-20<BR>\n" );
document.write( "-4y=-16<BR>\n" );
document.write( "-4y/-4=-16/-4<BR>\n" );
document.write( "y=4<BR>\n" );
document.write( "Now let y=4 in E2 and solve for x:<BR>\n" );
document.write( "x=10-3(4)<BR>\n" );
document.write( "x=10-12<BR>\n" );
document.write( "x=-2<BR>\n" );
document.write( "The answer is (x,y)=(-2,4)<BR>\n" );
document.write( "Check:<BR>\n" );
document.write( "E1) 2(-2)+2(4)=4<BR>\n" );
document.write( "-4+8=4<BR>\n" );
document.write( "4=4  So far we're right.<BR>\n" );
document.write( "E2) (-2)=10-3(4)<BR>\n" );
document.write( "-2=10-12<BR>\n" );
document.write( "-2=-2  We're completely right!!!<BR>\n" );
document.write( ":<BR>\n" );
document.write( "4. <BR>\n" );
document.write( "E1)  y=7-x<BR>\n" );
document.write( "E2)   2x+3y=-1<BR>\n" );
document.write( "Let y=7-x in E2 and solve for x:<BR>\n" );
document.write( "2x+3(7-x)=-1<BR>\n" );
document.write( "2x+21-3x=-1<BR>\n" );
document.write( "-x+21=-1<BR>\n" );
document.write( "-x+21-21=-1-21<BR>\n" );
document.write( "-x=-22<BR>\n" );
document.write( "-(-x)=-(-22)<BR>\n" );
document.write( "x=22<BR>\n" );
document.write( "Let x=22 in E1 and solve for y:<BR>\n" );
document.write( "y=7-22<BR>\n" );
document.write( "y=-15<BR>\n" );
document.write( "The answer is (x,y)=(22,-15)<BR>\n" );
document.write( "Check:<BR>\n" );
document.write( "E1) (-15)=7-(22) <BR>\n" );
document.write( "-15=-15  We're on the right track.<BR>\n" );
document.write( "E2) 2(22)+3(-15)=-1<BR>\n" );
document.write( "44-45=-1<BR>\n" );
document.write( "-1=-1  We're on a roll!!!<BR>\n" );
document.write( "Happy Calculating!!!!                   <BR>\n" );
document.write( "ISBN: 0-03-070039-6 pg 756 1-4 plus #6 ch 7.2 </SPAN>\n" );
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