document.write( "Question 70479: \r
\n" ); document.write( "\n" ); document.write( "The solution of the system 4x+5y =2 and 6x-2y=b is (3,a). Find the values of a and b. \r
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Algebra.Com's Answer #50299 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Start with \"4x%2B5y=2\"
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\n" ); document.write( "The fact that the point (3,a) satisfies the system of equations (that means it satisfies both equations), tells you that when x = 3 and y = a, the equation \"4x%2B5y+=+2\"
\n" ); document.write( "is satisfied. So plug in 3 for x and a for y. When you do, the equation becomes:
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\n" ); document.write( "\"4%2A3+%2B+5%2Aa+=+2\"
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\n" ); document.write( "This simplifies to:
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\n" ); document.write( "\"12+%2B+5%2Aa+=+2\"
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\n" ); document.write( "Subtract 12 from each side of this equation to get:
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\n" ); document.write( "\"5%2Aa+=+2-12+=+-10\"
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\n" ); document.write( "Finally, divide both sides by 5 to get:
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\n" ); document.write( "\"a+=+-10%2F5+=+-2\"
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\n" ); document.write( "So now you know that a = -2 and that is one of the things you had to find. You can substitute
\n" ); document.write( "this into the point (3,a) which is known to work in both equations because it is the solution
\n" ); document.write( "to the system of equations. By substituting -2 for a you know that the point (3, -2) satisfies
\n" ); document.write( "both equations.
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\n" ); document.write( "The second equation of the system of equations is:
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\n" ); document.write( "\"6x+-+2y+=+b\"
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\n" ); document.write( "Since you know this equation is satisfied by x = 3 , y = -2 you substitute these values into
\n" ); document.write( "the equation and both sides should be equal. By substitution the equation becomes:
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\n" ); document.write( "\"6%2A3+-+2%2A%28-2%29+=+b\"
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\n" ); document.write( "Multiplying out the terms on the left side results in:
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\n" ); document.write( "\"18+%2B+4+=+b\"
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\n" ); document.write( "and adding the two terms on the left side tells you that b = 22. That is the second
\n" ); document.write( "quantity that you were supposed to find.
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\n" ); document.write( "Hope this helps you to see your way through this word problem OK.
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