document.write( "Question 70479: \r
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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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document.write( "Helpp \n" );
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Algebra.Com's Answer #50299 by bucky(2189)![]() ![]() ![]() You can put this solution on YOUR website! Start with \n" ); document.write( ". \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 \n" ); document.write( "is satisfied. So plug in 3 for x and a for y. When you do, the equation becomes: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "This simplifies to: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Subtract 12 from each side of this equation to get: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Finally, divide both sides by 5 to get: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \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. \n" ); document.write( ". \n" ); document.write( "The second equation of the system of equations is: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \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: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \n" ); document.write( "Multiplying out the terms on the left side results in: \n" ); document.write( ". \n" ); document.write( " \n" ); document.write( ". \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. \n" ); document.write( ". \n" ); document.write( "Hope this helps you to see your way through this word problem OK. \n" ); document.write( " |