document.write( "Question 877947: 2x^2+3x-9=0 Complete the Square.\r
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document.write( "I know how to do it all the way up till when it should look like this: x^2+ (3x/2)+(9/16)=(81/4)+(9/16). It's adding the fractions to the right that doesn't make sense. I get 90/64, but mymathlab tells me i should have 81/16. **ugh* my mathlab makes everything more complicated by making me square root and square and cube fractions, and not put it in decimal form, so some help would be much obliged. \n" );
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Algebra.Com's Answer #529618 by richard1234(7193)![]() ![]() You can put this solution on YOUR website! Easier would be to factor 2 out first: 2(x^2 + (3/2)x - 9/2)\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Since half of 3/2 is 3/4, we want it to look something like 2(x + 3/4)^2 + constant. 2(x + 3/4)^2 has a constant term of 2*(3/4)^2 = 9/8, and we want 9, so add 63/8.\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( "Completed square form: 2(x + 3/4)^2 + 63/8 (can be checked via Wolfram Alpha) \n" ); document.write( " \n" ); document.write( " |