document.write( "Question 845824: Need help solving ASAP! Use the substitution method to solve the system of equations.
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document.write( "4(x - 2) = 8(y - 1)
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document.write( "16y - 32 = 2x + 4 \n" );
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Algebra.Com's Answer #509468 by pmesler(52)![]() ![]() You can put this solution on YOUR website! This one was fun. The key to solving this is to simplify first. Let's start off by labeling the different equations as equations 1 and 2\r \n" ); document.write( "\n" ); document.write( "1) 4(x - 2) = 8(y - 1) \n" ); document.write( "2) 16y - 32 = 2x + 4\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "The first thing you want to do is simplify equation 1 by using the distributive property to simplify both sides of the equation.\r \n" ); document.write( "\n" ); document.write( "So equation 1 looks like this after using the distributive property:\r \n" ); document.write( "\n" ); document.write( "4x-8 = 8y-8 \r \n" ); document.write( "\n" ); document.write( "Now, once we have this simplified we want to simplify it even more. Let's try to get the y alone. We do that by dividing both sides by 8 to get this:\r \n" ); document.write( "\n" ); document.write( "1/2x-8 = y-8 \r \n" ); document.write( "\n" ); document.write( "Now we just add 8 to both sides to get y by itself and we get this:\r \n" ); document.write( "\n" ); document.write( "y = 1/2x. \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "So now we can express y in terms of x. Now let's use that knowledge to solve for equation 2\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Equation 2 says \n" ); document.write( "16y - 32 = 2x + 4.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now all you need to do is substitute what we know y is into the equation and solve for x since we can now express y in terms of x.\r \n" ); document.write( "\n" ); document.write( "16(1/2x) - 32 = 2x + 4. Now, solve for x.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Equation 2 becomes \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "8x - 32 = 2x + 4.\r \n" ); document.write( "\n" ); document.write( "Subtract 2x from both sides\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "6x - 32 = 4 \r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Add 32 to both sides.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "6x = 36\r \n" ); document.write( "\n" ); document.write( "Divide each side by 6.\r \n" ); document.write( "\n" ); document.write( "x = 6\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "And since we know that y =1/2x that means y = 3. \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Now plug in the values of x and y into the original equations to see of they check out.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "4(6-2) = 8(3-1)\r \n" ); document.write( "\n" ); document.write( "4(4) = 8(2)\r \n" ); document.write( "\n" ); document.write( "16 = 16. Everything checks out for equation 1 so let's try equation 2\r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "16(3)-32 = 2(6) + 4\r \n" ); document.write( "\n" ); document.write( "48 - 32 = 12 + 4\r \n" ); document.write( "\n" ); document.write( "16 = 16. Equation 2 checks out so the solution is (6,3). \r \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |