document.write( "Question 66146: Please help with this problem that is through a practice CD class. I know that it's probably not as hard as I'm making it.\r
\n" ); document.write( "\n" ); document.write( "Solve for X and Y in the following problems and show your work:\r
\n" ); document.write( "\n" ); document.write( "a. X + Y = 6; 2X + Y = 8
\n" ); document.write( "b. 7X + 3Y = 14; 5X + 9Y = 10
\n" ); document.write( "c. 4X + Y = 16; 2X + 3Y = 24
\n" ); document.write( "d. 12X + Y = 25; 8X - 2Y = 14\r
\n" ); document.write( "\n" ); document.write( "I appreciate your help.
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Algebra.Com's Answer #46914 by checkley71(8403)\"\" \"About 
You can put this solution on YOUR website!
X+Y=6 & 2X+Y=8 THEN X=6-Y FROM THE FIRST EQUATION. NOW SUBSTITUTE (6-Y) FOR X IN THE SECOND EQUATION THUS:
\n" ); document.write( "2(6-Y)+Y=8 & SOLVE FOR Y THUS:
\n" ); document.write( "12-2Y+Y=8 COMBINE THE Xs & SUBTRACT 12 FROM BOTH SIDES
\n" ); document.write( "-Y=8-12
\n" ); document.write( "-Y=-4 DIVIDE BOTH SIDES BY -1
\n" ); document.write( "Y=4 SOLUTION. NOW SUBSTITUTE 4 FOR X IN EITHER EQUATION THUS:
\n" ); document.write( "2X+4=8
\n" ); document.write( "2X=8-4
\n" ); document.write( "2X=4
\n" ); document.write( "X=4/2
\n" ); document.write( "X=2 SOLUTION
\n" ); document.write( "PROOF
\n" ); document.write( "X+Y=6
\n" ); document.write( "2+4=6
\n" ); document.write( "6=6
\n" ); document.write( "__________________________________________________________\r
\n" ); document.write( "\n" ); document.write( "7X+3Y=14 & 5X+9Y=10 MULTIPLY THE FIRST EQUATION BY -3 TO ELIMINATE THE Ys & ADD THEM
\n" ); document.write( "-21X-9Y=-42
\n" ); document.write( "5X+9Y=10
\n" ); document.write( "------------------------
\n" ); document.write( "-16X=-32
\n" ); document.write( "X=-32/-16
\n" ); document.write( "X=2 SOLUTION NOW SUBSTITUTE 2 FOR X IN EITHER EQUATION & SOLVE FOR Y
\n" ); document.write( "5*2+9Y=10
\n" ); document.write( "10+9Y=10
\n" ); document.write( "9Y=10-10
\n" ); document.write( "9Y=0
\n" ); document.write( "Y=0/9
\n" ); document.write( "Y=0
\n" ); document.write( "PROOF
\n" ); document.write( "7*2+3*0=14
\n" ); document.write( "14=14
\n" ); document.write( "----------------------------------------------------
\n" ); document.write( "4X+Y=16 & 2X+3Y=24 MULTIPLY THE FIRST EQUATION BY -3 & ADD TO ELIMINATE THE Ys.
\n" ); document.write( "-12X-3Y=-48
\n" ); document.write( "2X+3Y=24
\n" ); document.write( "-----------------------------
\n" ); document.write( "-10X=-24
\n" ); document.write( "X=-24/-10
\n" ); document.write( "X=2.4 SOLUTION. NOW SUBSTITUTE 2.4 FOR X & SOLVE FOR Y
\n" ); document.write( "4*2.4+Y=16
\n" ); document.write( "9.6+Y=16
\n" ); document.write( "Y=16-9.6
\n" ); document.write( "Y=6.4 SOLUTION.
\n" ); document.write( "PROOF
\n" ); document.write( "2*2.4+3*6.4=24
\n" ); document.write( "4.8+19.2=24
\n" ); document.write( "24=24
\n" ); document.write( "------------------------------------------------------
\n" ); document.write( "12X+Y=25 & 8X-2Y=14 MULTIPLY THE FIRST EQUATION BY 2 & ADD
\n" ); document.write( "24X+2Y=50
\n" ); document.write( "8X-2Y=14
\n" ); document.write( "-----------------
\n" ); document.write( "32X=64
\n" ); document.write( "X=64/32
\n" ); document.write( "X=23 SOLUTION NOW SUBSTITUTE 2 FOR X AND SOLCVE FOR Y
\n" ); document.write( "8*2-2Y=14
\n" ); document.write( "16-2Y=14
\n" ); document.write( "-2Y=14-16
\n" ); document.write( "-2Y=-2
\n" ); document.write( "T=-2/-2
\n" ); document.write( "Y=1 SOLUTION
\n" ); document.write( "PROOF
\n" ); document.write( "12*2+1=25
\n" ); document.write( "24+1=25
\n" ); document.write( "25=25\r
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